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Massively densified networks -- Why we need them and how we can build them
White Paper / Dec 2016 / 5G

Today's networks have an atomic, discrete architecture, but as technology develops and more users and devices become a part of the equation, they are evolving into more user-centric and pervasive networks.  Senza Fili and RCR Wireless come together to present this white paper on why densifying networks is a growing need and how we can optimize them to accommodate major traffic growth.

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REPORT Massively densified networks ? 2016 Senza Fili |1| Massively densified networks Why we need them and how we can build them Monica Paolini, Senza Fili We thank these companies for sponsoring this report: In collaboration with REPORT Massively densified networks ? 2016 Senza Fili |2| Table of contents I. Report: Moving to dense, pervasive networks 3 1. Densification is more than small cells or DAS or C-RAN. From atomic to pervasive networks 4 2. The emerging RAN taxonomy. Antenna coverage and baseband separation 8 3. The big question: Indoor / Outdoor 10 4. Drivers: Coverage / Capacity 11 5. Performance: Capacity / Latency 12 6. Architecture: Small cells / DAS 13 8. Network: Distributed / Centralized 15 9. Technology: Cellular / Wi-Fi 17 10. Unlicensed spectrum: LTE / Wi-Fi 18 11. Spectrum: Sub-6 GHz / Millimeter wave 20 12. Interference: Co-channel / Separate channel 21 13. Backhaul: Fiber / Wireless 22 14. Fronthaul: CPRI / Xhaul 23 15. Access point density: High / Low 25 16. Business model: Single operator / Shared deployment 26 17. Concluding thoughts. The role of operators in a densified, pervasive network 28 II. Vendor profiles and interviews 29 Anritsu 30 Ascom Network Testing 37 CommScope 44 InterDigital 52 Kathrein 59 Rohde & Schwarz 66 Samsung Networks 74 SOLiD 81 SpiderCloud Wireless 88 III. Operators? interviews 95 BT 96 DOCOMO Innovations 104 Carolina Panthers 110 Enterprise, anonymous 116 Glossary 120 References 122 REPORT Massively densified networks ? 2016 Senza Fili |3| I. Report: Moving to dense, pervasive networks REPORT Massively densified networks ? 2016 Senza Fili |4| 1. Densification is more than small cells or DAS or C-RAN. From atomic to pervasive networks We often equate densification with the small-cell deployments, usually in conjunction with Wi-Fi and DAS, that increase wireless network capacity to accommodate traffic growth. While small-cell deployments are certainly a central element in the densification process, densification itself is becoming the catalyst for a much deeper evolution in wireless networks, which is not limited to small-cell deployments, and which is enabled by demand drivers and new technologies but goes beyond the contribution that each of them separately brings. Today?s networks have an atomic, discrete architecture in which cells are the edge access elements and are all connected to a distinct, common core. In the initial stages of densification, operators increase the number and density of these elements with a surgically precise addition of small cells, DAS or carrier Wi-Fi elements, but the architecture remains fundamentally the same. As this process intensifies, these atomic networks start to change into what we call pervasive networks in this report. Others (notably among them, I Chih-Lin at China Mobile) have called them user-centric networks, as opposed to the traditional network- centric network. Pervasive networks are distributed. Edge elements of the network, such as small cells or DAS, get closer to users and devices. And devices themselves can become part of the access network itself, with device-to-device connectivity. With C-RAN and, more generally, virtualization, the cell as the fundamental self- contained element in the RAN ceases to exist. It is replaced by a multi-layer, multi- band set of antennas connected to a remote baseband. Devices within this model can connect to more than one antenna and, in a mobility scenario, switch from one antenna to the next without having to do a handoff, because the cell ID remains the same. This is the evolution model put forward by China Mobile?s no-more-cells approach and DOCOMO?s phantom cells. REPORT Massively densified networks ? 2016 Senza Fili |5| Demand is the main driver to densification. Traffic growth on wireless networks continues unabated as subscribers conduct more activities and a wider variety of them, over more mobile devices, and as IoT spreads. In turn, the increased coverage and capacity of densified wireless networks facilitate subscriber and IoT device access, and this drives a further increase in demand. Increasing network capacity to meet demand has become financially unsustainable in today?s atomic networks. Pervasive networks allow a more efficient use of network resources that will enable operators to provide the capacity and performance needed cost-efficiently. Outdoor small cells were the first solution to address the need for densification as a complement to Wi-Fi offload. Small cells can be deployed in both 3G and 4G networks, and can be combined with Wi-Fi, sharing spectrum with the macro layer. As operators started to test small cells and plan for deployments, though, they realized that moving to large-scale deployments of small cells required substantial operational and financial effort. Over the last few years, the entire wireless ecosystem has been working to find business models and technological solutions that meet the operators? performance and cost requirements. The rest of the report will discuss the advancements in this area and how they relate to pervasive networks in detail. For now, we can call out 5G and virtualization as the crucial technology enablers in the transition to pervasive networks. The two technologies combine the performance improvement, the cost effectiveness, and the flexibility that operators need to meet the growth in demand in their networks. The transition from atomic to pervasive networks has a major impact on wireless networks ? from technology, performance, usage model, and financial perspectives, as described in the table below. The evolution is not confined to wireless technology or network architecture. It affects the entire ecosystem, including subscribers, enterprise, and third-party players, as well as business, ownership, and operational models. Densification is necessary for wireless networks to meet demand, but many changes, are necessary to achieve the capacity and performance goals, and they will eventually transform today?s atomic networks into pervasive networks. REPORT Massively densified networks ? 2016 Senza Fili |6| Atomic networks Pervasive networks Network model Network-centric: subscriber adapts to the network (e.g., goes to the window to make a phone call). User-centric: network adapts to subscriber demand (e.g., ultra-dense wireless infrastructure in stadiums). RAN Discrete elements: cells (antenna and baseband). No-more-cells, phantom-cells approach, with antennas as access points in a multi-layer topology, connected to a remote baseband. UE-RAN connection One-to-one connection from the UE to the cell. Handoffs required for the UE to move association from one cell to the next. UEs can connect to multiple antennas, use multiple bands. Flexible modes of connectivity coexist: dual connectivity, device-to- device connectivity, Wi-Fi offload. Subscriber can establish multiple concurrent connections: multiple devices (including non-SIM and IoT devices) on the same plan. Distinction between RAN elements and devices is less sharp because devices connect to each other and act as access points to the RAN. User and control planes User and data planes allocated to each access channel (e.g., sector). Control plane can manage traffic for multiple access channels, so some access channels do not require a separate control plane (e.g., LTE in unlicensed bands, LWA, mmW). Short-range mobility can be managed without handoffs. Densification targets Coverage in the wide area, capacity in high-traffic areas, with most of the RAN infrastructure in outdoor locations and large venues (e.g., stadiums). Vertical capacity increase and coverage extension driven by location- specific traffic or service requirements (e.g., service tied to a venue; IoT service). Layers Single macro-layer, possibly with limited small-cell hotspot deployments, and with Wi-Fi offload. Multi-layer networks, with extensive indoor and outdoor coverage with small cells, DAS or femto cells. Spectrum Cellular frequencies below 3 GHz. Wider range of higher-frequency bands (3.5 GHz, 5 GHz, mmW), with the inclusion of unlicensed spectrum. Core/RAN Separate location and equipment, with RAN equipment located at the edge and core equipment in centralized locations. Boundaries less strict, with RAN becoming virtualized and centralized, and some wireless core functionality moving to the edge (e.g., MEC, CORD). Location of function (distributed versus centralized architectures) is a strategic decision. REPORT Massively densified networks ? 2016 Senza Fili |7| Atomic networks Pervasive networks Testing, monitoring, optimization Testing and monitoring based on network KPIs and historical data. Limited optimization functionality. QoE metrics based on performance of UEs are tied to network KPIs to test, monitor and optimize networks in real time. Performance yardstick Capacity per RAN element. Capacity density (e.g., per sq km) and latency. Traffic management Maximize throughput. Capacity determines service availability. Real-time traffic management, at the application or service level. Network slicing used to extract more value from network resources. RAN equipment location Telecom assets (e.g., macro-cellular towers, building rooftops), mostly in outdoor locations. RAN equipment gets closer to subscribers and devices ? closer to the ground and indoors. Network ownership Operator owns network, often leasing space on cell tower or other assets. Limited network sharing. Venue owners increasingly pay for infrastructure, even though they do not (and choose not to) operate the network. Multi-operator, neutral-host model, in which some network elements (e.g., backhaul) are shared among operators. Control Operators control end-to-end network. Operators retain control of the RAN, but other players ? venue owners, residential users, neutral hosts and system integrator ? get more visibility into the networks and have a stronger role in determining how the network resources they paid for are being used. REPORT Massively densified networks ? 2016 Senza Fili |8| 2. The emerging RAN taxonomy. Antenna coverage and baseband separation Densification dictates an evolution of the RAN that involves all its elements. For operators, densification for capacity purposes starts with the macro networks. When operators need more capacity in an area, they typically first densify the macro network where possible, by adding cell sites, splitting sectors or adding new channels or bands. At some point this becomes financially too expensive or difficult (e.g., in environments where antenna density is already high, or where it is difficult to find new cell sites), and operators move densification to sub-layers ? micro cells, small cells or femto cells. DAS deployments typically run in parallel, to address high-density venues such as stadiums or enterprises. Distinguishing among different RAN elements, from macro cells to femto cells, including DAS, has become increasingly difficult. Many solutions are available to address specific environments, and do not neatly fit into any of the traditional RAN element groups. Rather, there is a continuum of solutions that are needed jointly, to address the varying requirements of different environments. This is a welcome evolution that testifies to the increased awareness of the multitude of environments where we need further densification, and the specific challenges that each presents. At the same time, the trend toward C-RAN and, more generally, toward the virtualization of the RAN creates a second dimension by which to define RAN elements. The first dimension is the antenna coverage area, which decreases in the move from macro to femto cells, but without well-defined borders among the different element types. The new, second dimension is the location of the baseband. In a distributed, traditional RAN, the baseband is at the cell site at the edge. In a centralized network, the baseband is located remotely. There are different types of baseband separation, depending on the type of fronthaul used ? and the type of functional split that defines different types of xhaul. REPORT Massively densified networks ? 2016 Senza Fili |9| Like macro cells, small cells can be distributed or centralized. Small cells and C-RAN are often presented as alternatives to each other, and small cells are seen as competing with DAS. However, within the frame of the densification process, small cells and DAS converge to a set of solutions with varying degrees of centralization ? with DAS being always centralized, and small cells being either centralized or distributed. As a result, we end up with a continuum of solutions on both axes. This helps operators find a solution that is well-tailored to their needs and helps vendors create differentiation in the marketplace ? but it also increases the complexity of the selection process. REPORT Massively densified networks ? 2016 Senza Fili |10| 3. The big question: Indoor / Outdoor Mobile phones were initially developed to provide the wide-area connectivity that wireline phones could not provide. The first mobile phones used satellites for access and were car phones, and there was widespread doubt that mobile phones could be of any use in areas like Manhattan?s urban canyons or for more than short calls. Today the situation is reversed. Most traffic ? 80% or more in most markets ? comes from indoor locations, and over 90% is data. Yet most of the RAN infrastructure, if we exclude Wi-Fi, is located outdoors; as a result, indoor coverage and capacity are more limited than outdoor. As wireless has become the default communication interface, the ability to provide the same level of service indoors and outdoors becomes a high-priority requirement for mobile operators ? and one that, in most locations, cannot be met cost-effectively with only outdoor RAN infrastructure taking an outside-in approach. Wi-Fi has been a boon for mobile operators: it transports the bulk of traffic from mobile devices, and most of that traffic is from indoor locations ? public venues, enterprise locations, homes. While Wi-Fi continues to complement cellular access, mobile operators want to improve indoor cellular coverage, both to meet the demand from indoor subscribers and to relieve pressure on the macro network. Indoor traffic typically is more expensive to carry than outdoor traffic, because it uses less efficient modulation schemes and hence uses more network resources. As a result, in recent years, operators have expanded their indoor coverage efforts. With the exception of some Asian countries, particularly Japan and Korea, mobile operators have been cautious about in-building networks, with the exception of large venues such as stadiums. Indoor coverage presents its own challenges, which are markedly different from those in outdoor deployments. The technology, the solutions and the business models are different, and they are evolving along with the relationship among venue owners, operators, and third-parties. REPORT Massively densified networks ? 2016 Senza Fili |11| 4. Drivers: Coverage / Capacity The narrative of wireless network deployments is in many ways all about densification. Mobile network performance and capacity have improved tremendously, thanks to technological innovation and greater spectrum availability, and densification has been a key part of that improvement. Initially densification was used to address coverage holes, or establish more consistent coverage. With the growth in data usage, capacity requirements have become a major driver to densification ? and densification has become a top priority for operators. Increasingly, however, coverage and capacity have intertwined. Just being able to receive a signal at a given location is no longer sufficient for coverage there. Depending on the market, location and operator, the capacity required for adequate coverage varies, and it is becoming meaningless to define coverage without reference to minimum capacity requirements. As a result, a location that was deemed to have coverage in the past may no longer have basic coverage, and it becomes a new densification target in order to achieve sufficient capacity. At the same time, boosting capacity in a hotspot may improve coverage in the surrounding area. An example is indoor infrastructure that addresses the demand created by indoor user offloads from the macro network serving the location; boosting that hotspot?s capacity also increases the capacity and coverage area of the macro network. In this case, the small cells or DAS in the indoor deployment not only increase the capacity density within their footprint, they also improve performance and coverage in the wider area. The co-dependency of RAN elements within the same footprint in determining both capacity and coverage demonstrate the need ? and benefits ? of looking at densification efforts within all the layers of the RAN environment rather than on the RAN elements ? e.g., small cells or DAS ? that are directly involved. REPORT Massively densified networks ? 2016 Senza Fili |12| 5. Performance: Capacity / Latency Capacity and coverage are the drivers to densification: they make it possible for operators to support the services that subscribers pay for. But capacity and coverage are no longer sufficient to make these subscribers happy. QoE, the quintessential ? if somewhat elusive and difficult to quantify ? measure of subscriber happiness, is increasingly determined not just by service availability (enabled by coverage and capacity), but by latency, as well as other transmission metrics such as jitter and packet loss. Latency?s rise to prominence is due to the increased use of real-time data applications: streaming video and audio (such as YouTube, Spotify), voice (including VoLTE, OTT voice), entertainment and gaming (e.g., Pok?mon). Some IoT applications ? e.g., connected cars, safety, monitoring, medical, financial ? have tight latency requirements, too. With real-time applications, poor coverage, congestion and high latency affect QoE in comparable ways: they create a poor subscriber experience, with subscribers giving up on the application they want to use, or with application becoming unavailable. Common effects of high latency include delays on voice calls and games, and, with video, frozen streams, dropped frames, pixelization or long startup times. As operators plan to increase coverage and capacity via densification, the ability to use low- and, as we move to 5G, ultra-low latency becomes a determinant when choosing the end-to-end network topology. The RAN plays a crucial role in latency, but so do backhaul/fronthaul, transport, core functionality, application and content processing and availability; they all need to be factored into network deployment and optimization for densified networks. REPORT Massively densified networks ? 2016 Senza Fili |13| 6. Architecture: Small cells / DAS Small cells and DAS are frequently considered to be competing solutions taking opposed approaches to densification. Historically they have developed to address different requirements: small cells mostly for capacity, DAS mostly for coverage. They generally serve different environments, as well: small cells in outdoor and small-venue / residential locations, DAS for indoor environments and large outdoor venues (although DAS can also be deployed in other outdoor locations). But DAS and small cells are quickly converging in a varied set of solutions that address the varied needs of venue owners and operators, and that combine features of both small cells and DAS. Both small cell and DAS vendors have increasingly expanded their portfolio to include both solutions or hybrid solutions (e.g., CommScope?s OneCell, Ericssons?s Dot and Huawei?s LampSite). RAN virtualization pushes small cells even closer to DAS. Furthermore, DAS is a precursor of C-RAN. This is especially true of active DAS topologies that allow a higher level of control over the management of network resources. An additional push for the convergence comes from the need to address medium- size venues ? sometimes referred as the middleprise. Most in-building deployments target large venues because of those locations? prominence and the dense demand there. Wireless performance during the Super Bowl, for instance, is tracked at an unparalleled depth. Locations like stadiums attract much attention and investment from venue owners and operators. Smaller venues are a much larger market (e.g., in terms of footage), but are much more challenging to cover profitably, because that market is fragmented and, with some exceptions, smaller venues do not have high capacity requirements or high REPORT Massively densified networks ? 2016 Senza Fili |14| revenue opportunities. Hybrid solutions and variations on the established DAS and small cell solutions ? especially when coupled with some degree of virtualization ? are necessary to address mid-size venues. At the same time, the ability to cover mid- size venues is crucial to the transition to massively densified networks, because of the amount of traffic generated by subscribers at these locations. REPORT Massively densified networks ? 2016 Senza Fili |15| 8. Network: Distributed / Centralized One of the main decisions operators have to make as they densify their networks is how distributed or centralized the RAN and core functions should be to maximize spectrum and resource utilization, optimize performance, and keep costs down. The dominant approach to RAN densification in today?s atomic networks ? with the exception of DAS ? starts with a phase in which densification is distributed: small and femto cells that include all eNB functionality ? radio and baseband ? are deployed at the edge of the network, often in places where the macro network has insufficient coverage or none at all. This approach makes small and femto cells fast and easy to deploy, because no central location is needed to host baseband functionality. Backhaul requirements can be easily managed because of the lower capacity and latency requirements of a centralized environment. Centralized architectures, such as DAS, C-RAN and vRAN, present multiple advantages over distributed topologies. Cost benefits that accrue from concentrating baseband processing in a remote location apply to all RAN elements, from macro to small cells. Femto cells may benefit from some level of centralization, but typically the approach to virtualization is different because femto cells do not have cost- effective access to fronthaul. Cost is a key consideration in driving RAN centralization and virtualization of the macro infrastructure in the short term, but the performance and flexibility advantages are going to have a stronger impact in the mid to long term, especially in HetNet multi-layer environments. Cost savings are less for small- cell than for macro-cell deployments, because centralized topologies require fronthaul instead of backhaul to meet latency and capacity requirements, and fronthaul is typically expensive and accounts for a larger percentage of the capex and opex in a small-cell network than in a macro-cell network. First among the benefits of a centralized architecture is the ability to manage transmission across multiple layers to minimize the effect of interference in co- REPORT Massively densified networks ? 2016 Senza Fili |16| channel environments. Especially in outdoor environments where macro and small cells overlap in coverage and use the same spectrum channel, interference severely cuts into the capacity benefits of small cells; interference reduces the capacity not only of the small cells, but of the macro cells, which are more expensive and valuable on a per-bit basis. Indoor small cells and DAS deployments suffer less from interference. The reduced coverage from the macro network, which is what drives in-building deployments, means interference is also more limited. New building codes that shield buildings from macro transmissions further reduce indoor coverage and interference, and indirectly foster a stronger commitment from mobile operators and the enterprise toward indoor deployments. In this environment, a centralized architecture is often beneficial, because it helps manage intra-layer interference, and it makes equipment installation and operation easier. Centralized deployments also enable ? but do not require ? new ways to manage traffic in dense environments. Cell IDs can encompass multiple antennas and multiple RATs can be tightly integrated, such as in China Mobile?s no-more-cells model and in DOCOMO?s phantom cells. A centralized, virtualized RAN is better suited to load balancing traffic across antennas and wireless interfaces, and to managing network-sliced traffic, because all the processing is done in a single location where there is full visibility across the real-time load and availability of the locally available network resources. Finally, a centralized architecture increases the efficiency of instruments like MEC that shift the core functionality to the edge ? for instance, to lower latency (e.g., for video streaming), or to support venue-specific applications (e.g., local breakout for enterprise or IoT applications). In this case, deploying MEC in a C-RAN is less expensive and more efficient than in a distributed RAN, because less equipment is needed and better coordination can be achieved. For instance, content caching is more efficient in a centralized environment, where it is available to multiple access locations, than in a distributed RAN in which the caching is done at each access location. REPORT Massively densified networks ? 2016 Senza Fili |17| 9. Technology: Cellular / Wi-Fi By far the most successful densification strategy to date has been Wi-Fi offload. It is Wi-Fi that has replaced wireline with wireless as the default access technology, not cellular. It was Wi-Fi that showed us what mobile broadband could do. When the iPhone came out, 3G networks did not have sufficient capacity to reliably support bandwidth-intensive services like video streaming, but Wi-Fi did, and it provided many subscribers the motivation to buy the new device. According to Cisco VNI, Wi-Fi carries 43% of the IP traffic today, and VNI forecasts this percentage to grow to 50% by 2020. By comparison, cellular traffic accounts for 5% today, and that is forecast to be 16% in 2020. This means the dominant access technology for mobile devices is mostly outside operators? control. Despite the growth in carrier Wi-Fi and, more generally, the increased push for Wi-Fi offload ? for data, but also for voice with Wi-Fi Calling ? it is the active choice of subscribers that has made Wi-Fi access prevalent, enabled by the wide availability of Wi-Fi infrastructure in residential and enterprise environments. Wi-Fi is set to continue to play a crucial role as wireless networks densify, but at the same time the 2.4 GHz and 5 GHz spectrums it uses are getting congested ? and the congestion will increase with the introduction of LTE access in the 5 GHz band (see below). Wi-Fi will expand to the 60 GHz band, but the dominant use cases there are for services in which the devices are in close proximity to the access point and fundamentally stationary. As a result, Wi-Fi is likely to become the technology that, instead of providing offload, will need offload itself. An expansion in the allocation of unlicensed spectrum that Wi-Fi may use will bring relief, but we will also need greater availability, higher spectral efficiency and more intensive utilization of cellular bands. Densification can no longer be primarily entrusted to Wi-Fi; it will instead require the integration of multiple access technologies to provide the seamless connectivity that users expect. REPORT Massively densified networks ? 2016 Senza Fili |18| 10. Unlicensed spectrum: LTE / Wi-Fi Wi-Fi?s success in winning the hearts of wireless users and in using spectrum with unprecedented efficiency, mostly because of dense deployments, has piqued the interest of vendors and operators that have seen an opportunity to use unlicensed spectrum for LTE. The advantages to mobile operators are clear: operators gain opportunistic ? i.e., not guaranteed, contingent on availability ? access to unlicensed spectrum, using the same technology and network infrastructure they use for LTE, maintaining control over traffic and integrating it with their cellular RAN and core. In addition, LTE?s spectral efficiency is higher than Wi-Fi?s because of more efficient modulation. With the exception of MulteFire (see below), LTE in unlicensed bands is deployed alongside licensed LTE, and, as a result, the marginal cost of adding LTE unlicensed is low in greenfield small-cell deployments. There are, however, disadvantages to using LTE instead of Wi-Fi in unlicensed bands as well. Wi-Fi is already installed in virtually all mobile-broadband devices. The infrastructure is widely available, and in most cases free to access ? both to operators and to subscribers. In contrast, LTE in unlicensed spectrum requires new devices and new infrastructure that has to be deployed ? and paid for, in most cases ? by the operator. Besides, in order to use LTE in unlicensed bands without unduly affecting Wi-Fi performance, LTE has to use LBT mechanisms that reduce its performance advantages over Wi-Fi. Finally, deployments of LTE unlicensed require the consent of venue owners where they have control over the location of the LTE unlicensed antennas. Those owners might not grant permission to install, because LTE unlicensed ? even when it uses LBT ? competes with the local Wi-Fi for network resources, which venue owners consider theirs and want to continue to control. It is still unclear how widely LAA, the version of LTE unlicensed that is designed to guarantee nice coexistence with Wi-Fi and which is deployable worldwide, REPORT Massively densified networks ? 2016 Senza Fili |19| worldwiwill be adopted in the face of the competition from Wi-Fi and the tradeoffs it requires. A further uncertainty is due to two promising ? and to some extent complementary ? alternatives: MulteFire and LWA. MulteFire allows for the use of LTE as the air interface in the 5 GHz band, without needing to use a licensed band for the control plane. So venue owners or operators that do not have an LTE network in licensed bands can deploy MulteFire and, if they choose, offer LTE unlicensed access on a neutral-host basis to mobile operators. This approach enables operators to improve capacity and/or coverage in venues where they may not have access or where they do not want to deploy licensed LTE. LWA allows mobile operators to use unlicensed spectrum but operates in the opposite direction of LAA. It uses the Wi-Fi air interface, but it fully integrates the Wi-Fi traffic within the LTE network. This approach removes the controversial coexistence of LTE and Wi-Fi in the unlicensed 5 GHz band, but it also removes the LTE performance advantage. As long as devices can support LAA, MulteFire and LWA (and they likely will), mobile operators will have multiple ways to use unlicensed spectrum in addition to Wi-Fi ? as long as they get access to the venues they want to cover. We expect operators to select one or more of these solutions, as soon as they deploy small cells, because using unlicensed spectrum not only augments capacity, it significantly improves the business case for small cells, which to date has been a difficult one. REPORT Massively densified networks ? 2016 Senza Fili |20| 11. Spectrum: Sub-6 GHz / Millimeter wave Massive densification requires new spectrum to manage the increase in traffic loads and meet performance requirements efficiently and cost effectively. By packing the infrastructure closer and using multiple layers (e.g., small cells and macro cells), operators can reuse a frequency channel more intensely. But at some point they face a diminishing return: the marginal investment to increase capacity becomes too high for the increase in performance it brings. Many operators face this situation in the macro RAN. They increase the density of base stations, added MIMO and CA, and split sectors, and they reach a plateau. The next step is to add small cells in the same band, but that introduces interference ? especially if the small cells are located outdoors in areas covered by the macro layer. In some environments the interference can be managed effectively, but it adds a cost in terms of effort and lost spectral efficiency. Using multiple bands to cover the same location enables operators to lower the impact of interference and minimize costs. Low-frequency bands are still valuable for improving coverage in low-density areas and for some IoT applications. In high- density environments, higher-frequency bands are more effective in reducing the interference and increasing spectrum utilization, because of the more limited coverage range. This is a major limitation in a macro network, and for this reason mobile operators have been reluctant to use spectrum above 2.5 GHz to date. Increasingly, however, mobile operators have become keen to use higher frequencies for lower layers. Candidates range from the 3.5 GHz band to the unlicensed 5 GHz band, and all the way to mmW. The 3.5 GHz band is an excellent candidate for small-cell deployments, because its shorter range strikes a good coverage/capacity balance. However, the amount of spectrum available is limited, and in some countries there are regulatory restrictions or spectrum allocation issues that have been slowing down the plans to use the 3.5 GHz band. Millimeter-wave bands are the other hot prospect for spectrum expansion. The amount of spectrum available is huge and, because of the high reuse that high frequency makes possible, the potential increase in capacity is astounding. Spectrum in these bands is going to be much less expensive, or even usable on an unlicensed or lightly licensed basis, and current 5G standardization efforts cover mmW bands both for fixed wireless links (e.g., backhaul or possibly fronthaul) and for access in areas of very high density (e.g., where even small cells or DAS are not sufficient, the extremely hot spots). MmW supports densification on two fronts ? xhaul to small cells, and access from UEs ? which can be combined when using in- band xhaul. Using mmW for access requires more than new antennas or distributed small cells. Because of the small coverage radius, mmW access can generate large numbers of handoffs, as users will cross the cell-edge border frequently and move from mmW to sub-6 GHz cellular coverage from macro or small cells. Frequent handoffs create high levels of overhead that affects the anchor sub-6 GHz network. A solution to this problem is to implement a phantom-cell architecture, in which coexisting elements ? e.g., sub-6 GHz and mmW ? become part of the same cell ID and the control plane is managed for both bands from the sub-6 GHz bands, which have wider and more consistent coverage. Load balancing across bands enables operators to direct traffic to the band that can accommodate it more efficiently. Further densification and more intensive spectrum utilization may come from device-to-device communications ? either subscribers or IoT devices. Device-to- device communications can establish an ad hoc, mesh-like network that expands the reach and capacity of the rest of the network. This possibility calls into question the sharp boundary between network and device that is prevalent in today?s networks. REPORT Massively densified networks ? 2016 Senza Fili |21| 12. Interference: Co-channel / Separate channel Initial densification efforts with small cells and DAS have used a co-channel model in which they share spectrum with the macro layer, but generate different levels of interference. Femtocells, the first incarnation of small cells, were largely deployed indoors, at very low power and in places where macro coverage was weak or absent, and so interference was not a big issue. Outdoor small cells were initially deployed in many cases to address areas without coverage. Interference was, by definition, not an issue. When small-cell deployments moved to dense areas where operators had macro coverage but insufficient capacity, interference became a major issue that slowed the rollout of small cells. It also pushed operators to spend more money on increasing macro capacity, and to move to small-cell deployments as a last resort after all the macro enhancements had been used. Initially, techniques like CoMP or eICIC were not sufficiently mature or widely deployed, making interference management less efficient. But more fundamentally, interference between small and macro layers in co-channel deployments reduces the capacity of the macro layer, and that is highly undesirable and expensive for mobile operators. Even if the cost of installing a small cell is lower on a per-bit basis than a macro cell, the cost savings could easily dissipate if the small-cell installation results in a reduction of the macro-layer capacity. Of course, an effective way to minimize interference is to move away from co- channel deployments and use a separate channel. Operators largely resist this, because typically cellular spectrum is too expensive to use only in the small-cell layer. In most environments, a co-channel deployment supports a more efficient use of spectrum, in terms of capacity density (bits per sq km), than a deployment in which small cells use a channel different from that used by the macro layer. But the reduction of capacity from interference makes the business case for small cells less palatable, because it increases the overall network per-bit cost. As a result, operators have been reluctant to deploy small cells widely, and have focused on areas where the need for additional capacity makes them less sensitive to cost. Two ways to cope with the interference issues have emerged and are likely to accelerate massive densification. The first of these involves spectrum bands that are not traditionally used for mobile and that, therefore, are less expensive and in higher-frequency bands ? such as the 3.5 GHz, the unlicensed 5 GHz band and mmW bands. Operators can use these bands in addition to co-channel spectrum within the same small-cell enclosure, or they can deploy a sublayer in these bands and let the macro layer retain control of cellular spectrum. In both cases, the cost per bit decreases. In the first case the low incremental cost of adding these bands, coupled with the increase in capacity, reduces the per-bit capex and opex. In the second case the business case is strengthened by preserving capacity in the macro layer by avoiding interference. A second way of coping with interference is to move the lower-layer infrastructure indoors. In locations where per-small-cell deployment and operating costs are comparable or lower than in an outdoor environment, indoor networks can help reducing the per-bit capex and opex. The reduced impact from interference lowers the per-bit cost in indoor deployments. However, in-building infrastructure faces business model, ownership, and control challenges that are different from outdoor infrastructure, and access to indoor locations may not be available or affordable to mobile operators. The move to in-building infrastructure will undoubtedly intensify and accelerate the densification process, but it will not eliminate the need for outdoor infrastructure, which will still be used to meet demand from outdoor subscribers and in places where operators cannot deploy indoor infrastructure. REPORT Massively densified networks ? 2016 Senza Fili |22| 13. Backhaul: Fiber / Wireless A vexed question in the small-cell ecosystem is whether backhaul should be wireline (and, if so, whether it has to be fiber) or could be wireless (and, if so, in which bands). The debate does not regard indoor deployments, where wireline backhaul is typically used within the building. In outdoor environments, however, both wireline and wireless solutions present benefits and limitations ? and approaching backhaul as a combination of fiber and wireless links may help reduce the drawbacks of both technologies. Fiber is the ideal backhaul for outdoor small cells, but it is not always available, and even when available, it is not always cost effective. In most environments, fiber is available in the vicinity of the small cells, but bringing it to the small cell is often too expensive, not to mention time consuming. Wireless backhaul is the alternative, as long as small cells do not use a C-RAN or virtualized architecture. With remote baseband, fronthaul requirements are tighter and wireless fronthaul is possible, but it requires specialized solutions. Solutions that work for backhaul typically do not have enough capacity or a low enough latency to support fronthaul. The limitation of wireless backhaul is that to provide sufficient latency, line of sight from the small cell to the aggregation point is required. As the link length grows, the likelihood of having a reliable line of sight and reliable performance decreases. Multi-hop wireless backhaul can compensate for the lack of line of sight, but increases costs and latency. In outdoor environments, fiber and wireless are not mutually exclusive, but rather two components defining the backhaul. In fact, a mix of fiber and wireless backhaul is the dominant solution, with the choice between the two dictated by cost and availability tradeoffs. The backhaul for every small cell terminates into fiber; what changes is the length of the wireless backhaul, which can be zero for a small cell with fiber backhaul. REPORT Massively densified networks ? 2016 Senza Fili |23| 14. Fronthaul: CPRI / Xhaul Another concept that pervasive networks challenge is the dichotomy of backhaul and fronthaul in terms of requirements and what technologies could meet them, and in terms of what type of signal the fronthaul carries. Within mobile networks, fronthaul is the link from the RRH to the BBU, and backhaul the link from the BBU to the core network. If the RRH and BBU are co-located, there is no need for fronthaul. Because the fronthaul carries the analog signal, the bandwidth and latency requirements are much higher than those for backhaul. As a result, some technologies and solutions may be suitable only for backhaul. Others may be well-suited for fronthaul, but too expensive for backhaul. First off, with the move to extra-low latency and high capacity (e.g., when using mmW for access), the 5G backhaul requirements may approach those for fronthaul today. But this also means that fronthaul requirements, if using CPRI, will also grow to alarming levels. This creates the possibility that the fronthaul may become the bottleneck, and the risk that RAN capacity may have to be capped if the BBUs are remote. (Another possibility is that RAN virtualization will slow down because fronthaul requirements are too onerous.) Because it is difficult to meet current and future fronthaul requirements with CPRI, especially in small-cell deployments where dark fiber is too expensive or not available, there is considerable ongoing work to define alternative interfaces ? e.g., compressed CPRI or Ethernet ? and functional splits, in which some of the baseband functionality stays at the edge, co-located with the RRH. With functional splits, the fronthaul requirements decrease, but so do the benefits of virtualization. Multiple options are available, and operators need to decide what level of functional split works best in each location in their networks. It is not yet REPORT Massively densified networks ? 2016 Senza Fili |24| clear whether there will be a dominating functional split or which splits will be best suited to which environments. Importantly, functional splits call into question a clear-cut distinction between fronthaul and backhaul, and instead suggest a continuum of functional splits between RRH and BBU, which recently has been referred to as the xhaul. Then, depending on the type of xhaul ? i.e., the selected functional split ? and the RAN requirements, different interfaces and solutions become appropriate. The xhaul approach recognizes operators? need for flexibility as they densify their infrastructure and use a wide range of RAN solutions to strike the right balance between costs and performance. REPORT Massively densified networks ? 2016 Senza Fili |25| 15. Access point density: High / Low When planning for densification, operators need to select not only technologies, solutions, spectrum bands and locations, but also the topology of the densification. There, access point density is a choice that is becoming more prominent, although it is rarely discussed as a stand-alone dimension of the densification strategy. As a wider range of solutions, spectrum bands and business models become available, operators can choose among options that vary in power, coverage, cost, equipment size, and ability to fit into multi-operator, neutral-host models. Given a target capacity they aim to have in a given location, operators can choose to have a high number of low-power, reduced-coverage, low-capacity access points, or a smaller number of high-capacity access points. When using mmW for access, or multiple bands in the same access point, operators can create super hotspots where they have a very high concentration of traffic. The primary consideration in selecting the appropriate access-point density is the distribution of traffic. Subscribers and the traffic they generate are distributed very unevenly, so it is crucial to place the access points as close as possible to subscribers. If the distribution is uneven and highly clustered, access points will be placed more densely in high-usage locations. If the distribution is more even, access points with larger coverage areas may be preferred. In addition to traffic distribution across locations, operators need to consider backhaul availability, deployment costs, spectrum availability (including traffic load in unlicensed bands), business model (e.g., whether there is infrastructure sharing among operators or a neutral-host model) and RF propagation in the environment. For instance, if deploying access points is inexpensive, backhaul is easily available, or spectrum availability is limited, an operator may opt for a denser network of access points with limited coverage and capacity. Fewer but more powerful access points may be better suited in locations where installation and backhaul are expensive. REPORT Massively densified networks ? 2016 Senza Fili |26| 16. Business model: Single operator / Shared deployment Densification demands that the wireless infrastructure move closer to subscribers, vehicles, and IoT sensors and other devices ? and this means beyond the cell-tower model, which continues to be used for the macro layer but needs new indoor and outdoor models as complements. In a macro environment, the operator has full control over network planning, deployment and operations, using telco assets such as cell towers. The operator owns the end-to-end infrastructure and manages traffic and interference. Cell towers are usually owned by third parties, but operators lease space on them and retain control of the telecom equipment. This model, well understood by every player in the ecosystem, ensures that deployments proceed smoothly. In a sublayer deployment, this model no longer works. The access infrastructure has to be mounted on non-telecom assets, such as lampposts, exterior or interior building walls, ceilings, advertisement displays, and public transportation vehicles, or even below street level. This creates constraints on where operators can deploy the equipment; it also creates the need to establish direct or indirect relationships with the owners of these assets ? cities and public entities, enterprises, educational institutions and other venue owners. In some cases, these entities expect to extract rent from mobile operators or third parties working on their behalf. In other cases, the asset owner may pay for the infrastructure or encourage rent-free installation and operation, but may require visibility or some level of control over the local network. Negotiating deals with the new asset owners has proven to be one of the biggest challenges ? and causes of delay in deployments ? that operators face. Asset owners are eager to host the telecom infrastructure, either to extract revenues or to get better mobile service or both, but they do not know how to structure deals with operators because it is uncharted territory. The same is true for mobile operators. As a result, we see trials, negotiations and even legal challenges ? but little in the way of the expected large deployments. The urgency of densification is increasingly felt by both parties as bad wireless service affects operators and venue owners or administrators, and so deals are starting to come together. They will undoubtedly evolve through time as we understand the deployment models better from technical and business perspectives, but these early deals are the necessary first step to get beyond ad hoc densification to large-scale densification. More interestingly, the need for mobile operators and asset owners to work together ? directly, or indirectly through third parties such as service providers, fiber providers or cell-tower companies ? is also accelerating the development of closer relationships with cities, enterprises and other venue owners and institutions. These relationships can lead to better performance and to the creation of services that mobile operators can develop or support. In a densified, pervasive network, it is not just the equipment that moves closer to subscribers ? it is the relationship among subscribers, venue owners/administrators, and operators that becomes tighter and deeper. The need to negotiate deals with asset owners coupled with the need to find cost-effective ways to deploy small cells drives new business (and deployment) models. The initial small-cell business model assumed each operator would deploy its equipment independently of other operators or service providers, striking deals with asset owners. But that is too expensive, time consuming and inefficient to scale beyond prime locations (e.g., some parts of Manhattan, downtown San Francisco, central London) to areas with less concentrated, but still high, traffic. REPORT Massively densified networks ? 2016 Senza Fili |27| Especially in indoor venues, the trend is toward shared deployments, in which one operator or, more commonly, a neutral host acts as the interface between the asset owner and the operators that wish to participate in the local network. This is very similar to the DAS neutral-host model, in which multiple operators can share the DAS, but each controls its own transmissions. This model enables operators to reduce costs by sharing some of the infrastructure, and it streamlines deployment and operations, because the neutral host manages all the relationships with venue owners on one end, and with multiple operators on the other end. There is a widespread belief that the DAS neutral-host model does not work in small-cell deployments because it requires operators to share the RAN ? an option that nearly all operators consider unacceptable if it involves their licensed spectrum. But the neutral-host model can equally allow operators to deploy their own radios, retain control of the use of the spectrum and manage traffic, without having to negotiate a separate deal with the asset owners, and without having to directly deploy and manage the RAN equipment. This model does not exclude opportunities for the operators and venue owners to negotiate specific arrangements about network performance, coverage or functionality, or to provide additional services (e.g., enterprise services, or IoT services to city agencies). These arrangements will encourage the venue owners to participate more actively in the densification process ? in part by funding deployments, and in part by requesting services ? and to see the wireless infrastructure as an integral component of the venue, comparable to the in-building electrical network. In this context, the availability of the 3.5 GHz band in the US and of other sub-6 GHz bands in other countries will push the shared deployment business model further, because it allows neutral-host players to install a small-cell network in a venue, using spectrum bands that are not allocated to a specific operator. The venue owner or the neutral host can deploy the network and allow access to operators on a wholesale basis. A benefit of this approach is that the neutral host or venue owner can deploy a single network that can be shared, and this results in more-efficient spectrum utilization and in lower costs. REPORT Massively densified networks ? 2016 Senza Fili |28| 17. Concluding thoughts. The role of operators in a densified, pervasive network Many mobile operators worldwide question their future relevance ? and worry about their ability to extract the revenues they deserve from their networks. Typically, these concerns are rooted in the risk they perceive that they will become a dumb pipe that can transmit an increasing amount of data to their subscribers and do so more reliably than in the past, only to see subscribers value the networks less than the OTT apps they use on those networks. The transition to massively densified, pervasive networks can change this. The role of the mobile operator is transformed by the increased complexity of wireless networks that have to optimize and integrate multiple spectrum bands, technologies, services, device types and topologies. Mobile operators can no longer focus only on pushing as many bit/s as their infrastructure supports; they also need to manage traffic, applications and network resources in a much smarter way than they are accustomed to. Increasingly, they do not look like a utility ? they look instead more like orchestra conductors, coordinating transmission in a multi-layer network ? a network in which they have the flexibility to set strategy in ways that differentiate their network from that of their competitors. REPORT Massively densified networks ? 2016 Senza Fili |29| II. Vendor profiles and interviews REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |30| Profile Anritsu Founded over 120 years ago, Anritsu Corporation is a global provider of communications test and measurement solutions. Anritsu?s measuring instruments support multiple areas: ? Mobile wireless communications, RF and microwave: base station analyzer, Bluetooth and WLAN tester, cable and antenna analyzer, conformance test system, interference hunt, PIM analyzer, peripheral equipment, power meters and sensors, signal analyzer, spectrum analyzer, signal generator, signaling tester, shield box, trace management, vector network analyzer, handheld vector network analyzer ? Digital broadcast: Digital broadcast analyzer ? Devices and components test: Bit-error-rate testing, eye pattern analyzer, vector network analyzer, signal generator, optical spectrum analyzer, peripheral equipment ? Transport: IP/Ethernet testers, SDH/SONET/OTN analyzers, PDH/DSn analyzers, multi-layer network test platform ? Optical: OTDRs, multi-layer network test platform, optical loss test set / light source / optical spectrum analyzer, video inspection probe In addition, Anritsu has recently introduced SkyBridge Tools? to manage cloud data. SkyBridge Tools helps mobile operators with documentation and reports, real-time analytics, automated assessment of RF sweeps and PIM test results. The ability to automate and scale testing and monitoring in wireless networks is crucial for operators moving to multi-layer, multi-RAT networks and with DAS; the number of tests needed to assess performance rapidly increases with complexity and makes manual field testing time consuming and expensive in terms of staff resources. Anritsu solutions also help operators with densified networks to identify the different sources of interference that affect macro-cell and small-cell networks and to manage interference, if necessary, in real time. The portfolio of Anritsu measuring instruments is well suited for indoor densified networks. It consists of solutions for both the wireless and optical segments; they can test and monitor both the access and backhaul/fronthaul portions of mobile networks. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |31| Anritsu Managing interference in densified networks A conversation with Tom Elliott, Sr. Product Manager, Anritsu Company Monica Paolini: In this conversation with Tom Elliott, a Senior Product Manager at Anritsu in the United States, we discuss how testing evolves as operators densify their networks with DAS, small cells and other solutions. Tom, could you give us an introduction on the approach to densification at Anritsu and what your role is within the company? Tom Elliott: As far as personal work on densification, I?ve been heavily involved with redefining what field testing means for DAS. The idea of a test as being a return loss, or a distance- to-fault really isn?t working too well for the DAS people. We?ve also had a focus on received signal quality. I and others have been heavily focused on the idea of spectrum assurance, the idea that you can have a variety of ways to make sure that your uplink is clean. With LTE in particular, a clean uplink really helps capacity, and capacity is what densification is all about. Monica: You?re personally more involved in the DAS testing, but at Anritsu, you cover other areas with respect to densification, too. Tom: Personally, I?ve been involved in DAS testing and interference. Others in Anritsu are involved in the full range of tests that we do, as well as spectrum monitoring. Monica: What is different about DAS testing? The end result is to make sure that the QoE is good for the subscriber. Tom: In a tower installation test, you have cables going up the tower. You have antennas, maybe some splitters, and other passive RF components. A typical tower test would have 25, 50, 100, maybe even 150 sweeps of some nature. We?re talking about return loss, distance-to-fault, cable loss, PIM, and maybe some fiber test. That can be handled by the existing processes. When you move to a DAS system, especially a neutral-host DAS system, where you need to test three or four frequency bands on every cable, those tests multiply, and they multiply dramatically. A medium-sized DAS install could have several thousand tests. A football stadium, for instance, may have as many as 15,000 tests. It?s the sheer scale that becomes a problem. You?re talking about months, man-months, spent dealing with these tests. Monica: Is automation going to help this? Networks are becoming more complex, not less complex. How is testing going to evolve with the increase in complexity? Tom: Automation can help this. In manufacturing, for many years, there?s been a piece of software called a test executive. It sets up tests, it automates the tests, it runs the tests, it collects the results, and generates statistics. We need something similar to that for the field, something to automate the field tests, and DAS is a perfect setup to do this. At the same time, there?s the idea of removing some of the possibilities for error out of the DAS testing. In the work we?ve done with some of our DAS installers, we?re finding when we come in, there might be a 10% error rate on these files. Say I have 5,000 files, I sample 500 files. I can?t check every one of them, so I sample. I say, ?OK, it?s good.? I pass them off to my end customer. They look at 5,000 tests and say, ?What am I going to do with this?? They sample the tests. They sample different tests, and if there?s a 10% error rate, chances are they?re going to find some problems. The results all come back to the testing contractor, and we get into this loop. The problem was expressed to me best this way: ?I have 1,000 traces in a directory on my PC. Which ones are missing? Which traces are duplicated? Which traces are misnamed? I haven?t even gotten to which traces fail judgment.? The existing processes, which are based on a tower technique, just do not scale. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |32| Monica: Also, the DAS systems are evolving. With active DAS, DAS is becoming more complex. Tom: One thing Anritsu is doing is redefining what a test is. I?ve talked about a return-loss sweep, a distance-to-fault sweep, a cable-loss sweep, and about having to do these all at three different frequencies. Why do we need to run nine lab-based tests on each cable and deal with these individually? Don?t we have computers? Don?t they do things like this? We do have computers, and they do things like this. We can redefine what a test is, from ?Here?re all these things I have to do to this cable,? to ?This cable is good or bad.? We can remove some of these workflow issues. There?s a MOP, a Method of Procedure. Some companies call this a SOW, or statement of work. By necessity, it?s fairly general, but when a technician is faced with an ambiguous situation, what they?ll tend to do, rather than have to come back and test again, is they?ll take three, four, or five different traces, and let the engineers sort it out. Typing filenames on the instrument turns out to be a major time sink. Not only do they tend to make a typo once in a while ? you would, too, if it was 20 degrees out and blowing like anything ? but each technician tends to have his own naming standard, and they leave it to the engineer to sort it out. There?s also some ambiguity in the existing process for instrument setups, and this can lead to situations like ?Oh my goodness, it was the wrong start and stop frequency,? or ?The limit line was wrong,? or ?Something was wrong. We?ve got to go back and retest.? These sorts of things could be removed by test automation. Monica: In a DAS environment, you might have a neutral host, so it?s not necessarily the operator doing the testing. And the people that are doing the install and the testing might not be as qualified, or have so much RF experience. Doesn?t that create additional challenges? Tom: It certainly does, and I?ve been involved in some of these. DAS testing, even if you do have RF experience, is a different field than some of the other testing you may have done, and there are certain ambiguities there. What Anritsu has proposed is an automated field test solution. You may have heard of it by the name of SkyBridge Tools. It?s on our external website. It provides setup information for the instruments. It provides test automation when you?re on site, and it provides automatic judgment, automatic reporting with cloud-based dashboards, so everybody with a login knows exactly how the job is progressing. This way, the questions can be asked and answered while the technician is still on site, before they?ve closed out, before they?ve gone somewhere else, before they have to come back, before payment is delayed. Monica: Basically, you can see there is a problem, and then you can dig down specifically in that area, whatever the case may be. Tom: That?s exactly it. The idea is to get things done quickly and done now. Our field tests show that SkyBridge can cut the actual test time by up to 90%. That?s a big number, but if we?re going from a manual method to a computer-aided method, that?s not surprising. Monica: With densification, the more packed your infrastructure is, the more opportunities you have for interference. That is whether it?s indoors or outdoors. How do you deal with that? Tom: First, maybe I should take a moment and define what the interference mechanism is. Interference is a receive issue. Signals that get to the radio?s receiver affect the front end, and even if it?s not the signal you want, it will come in there. It will reduce the sensitivity of your radio receiver. This lowers the radio?s sensitivity, and increases REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |33| your bit error rate, increases your frame rate, increases your dropped calls and all that bad stuff. The name for this is receiver desense, or desensitization. If it?s severe, it?s called receiver blocking. One thing that seems to be a chronic misunderstanding about interference is that interference does not have to be on your receive channel. All it has to do is get to the input of your receiver. It can be on a different frequency. In other words, it can be in band, but it doesn?t have to be on channel, so your receive pre-filter matters. If it gets through your receive pre-filter, if it gets to the input of your receiver, it?s interference. Monica: In terms of the testing, how can you have your testing become more efficient where you have small cells, which are additional sources of interference, when small cells and macro cells are in co-channel deployment? Tom: Anritsu has a lot of interference solutions, but there?s one thing I need to point out, which is that the incoming signal amplitude at the receiver matters. Small cells have their own unique problems when it comes to interference. Let?s say I have a signal source, an interference source. It?s at -40 dBm. It?s emitting at -40 dBm. If that signal is a mile from a tower, propagation models say it?s going to lose 96 dB by the time it gets to the tower. In absolute numbers, It?s going to be -136 dBm at the tower. It?s not going to be an issue. The tower won?t see it. It won?t matter because it?s above the small cell?s noise floor. We can coexist perfectly happily. If we?re 50 ft from a small cell, the signal will lose 56 dB over 50 ft. That puts the signal at -96 dBm, at the small cell?s receive and it?s a problem for the small cell. My point here is that when you put in small cells, there?re going to be interference sources that will bother a small cell that a macro cell would never see. Interference becomes a bigger problem. Of course, the small-cell reception area is smaller. It?s a small cell, after all. But there are other interference sources that will matter to the small cell that a macro tower won?t see. Efficiency in finding interference becomes very important. Monica: How do interference sources change as you move from macro to small cells? Tom: It depends on the sort of sources we?re looking for. There?s on-channel interference, there?s interference that?s off channel but in band, there?s impulse noise, arcing, sparking. There are even still jammers around. We had a case a while ago where a high school teacher had a jammer running during his tests so his students couldn?t cheat, and it was shutting down an AT&T sector. Jamming 911 calls? Not good. We also have harmonics, multiples of an original signal. Some of our TV signal harmonics fall in the PCS band. There is intermodulation, both active and passive intermodulation, that we all know about from PIM testing. There?s something called the near-far problem, where a strong interference signal or a strong transmitter will overwhelm a weak desired signal. All of these are typical interference sources, and we?ve got a great app note on interference hunting concepts that goes over this in more detail. As far as making interference hunting more efficient, Anritsu does have a tool set for this, starting with some of the very simplest traditional methods. We?ve got the traditional direction-finding tools. We take a spectrum analyzer and a Yagi antenna, look for the strongest signal, and you triangulate. We have map-assisted tools that will actually put a map on a spectrum analyzer. We have car-based signal location, where we can go through and essentially seek the power. Do you remember the child?s game of hot and cold, where one child picks something, and the other child asks, ?Am I getting hot? Am I getting cold?? It sorts of works that way, and it?s surprisingly fast. Also, it?s reliable, because it takes care of issues with multipath, echoes, reflections, and even diffraction. Another solution is monitoring, because signals aren?t always interfering. We can characterize a signal by doing short-term monitoring. Every one of our spectrum analyzers is web enabled. You can hook them up to the internet. You can control them with a browser from a distance. We can drop something off at a site for a week, for two weeks, for three weeks, and see what?s happening. On the other hand, you might be interested in some long-term monitoring. We have a set of REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |34| headless spectrum analyzers designed specifically for this sort of task, which can be either temporarily or permanently in place, and we have software to go with it, so you can maintain your signal quality throughout your network as things change. The device is comfortably monitored remotely. Monica: There is testing that you do at the beginning, but then monitoring is an ongoing effort. Is the relationship between testing and monitoring evolving somehow, with densification and networks that are becoming more complex and dynamic? Tom: Back when we were mostly concerned about coverage, interference didn?t matter so much, because all of our cellular standards have redundancy, and they can handle a certain amount of interference without dropping the call. Every one of those methods of handling interference involves sending out more bits to get the same amount of data. In other words, you?ve affected your capacity. As soon as we moved to LTE and we were concerned about capacity and densification suddenly, interference matters, and it matters a lot, because it?s hitting your throughput directly. That?s why monitoring is becoming of interest to our customers. Network operators, especially, are concerned about their signal quality and their throughput. If I go back 10 years to CDMA, if we had any interference problem, it would be the easiest thing just to plunk a $4,000 board into a base station and bring up a new carrier, and all of a sudden, you have more capacity. That?s not possible with LTE. The bands don?t permit it. If you want to have more capacity, first you need to make the most out of the macro cells you have. That?s what spectrum monitoring is about. Second, once you get your small cells in, or your iDAS or your oDAS, you need to make sure it?s performing effectively. Monica: What is the impact that you?re seeing from densification on spectrum assurance? Tom: Spectrum assurance is Anritsu?s name for a family of spectrum monitoring, interference hunting, and signal mapping tools, both indoors and outdoors. We?re developing these in response to our customers? requirements for exactly the sort of capacity we?ve been talking about with LTE and densification. Monica: Where do you see testing moving in the future? Tom: We?re going to be moving closer to real time. We have all this communication capability now. Our instruments are using it and they will continue to use it. Cloud-based solutions are tremendously efficient. The test automation for DAS is a cloud-based solution. We?re going to see that. You?re going to see more control, you?re going to see more remote expertise, you?re even going to see remote dispatch coming in the future. Monica: You mentioned real time. What is real time for you in testing? Is it a day, an hour, a minute, a millisecond? Tom: Real time can be a day, it can be an hour, it can be a minute. Picture this scenario. There is an engineer at a central site somewhere in the world. There?s a technician on site in the field. The technician runs some diagnostics. He posts the results in the cloud. The engineer sees the results and downloads some more tests to the technician?s equipment. That sort of collaboration is what I am talking about. Monica: I guess at different sites, and for different needs, you might switch to different time granularity while there? Tom: Absolutely. Monitoring typically uses a 15-minute window. Troubleshooting would require updates in a few seconds. If we?re building a DAS system, maybe once a day is enough. It depends on the task. Monica: Monitoring allows you to identify and fix a problem, but also it allows operators to optimize the use of the network resources. Can you help them with that as well? Tom: Yes. We do have a product line that provides a big-iron software application, called Master Claw, that is a service-assurance solution. We also have a software application called Vision. It works with our long-term RF monitoring probes, and it helps characterize when signals occur and what they look like; it helps figure out where the signals are occurring, within a few blocks, by triangulation; and it provides all the necessary information to dispatch a team to go and find that signal. Now we can sit in a central place somewhere, let?s say somewhere in the US, characterize an REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |35| interference on three or four sectors in, say, Los Angeles, and dispatch a local team to go find it when we?re ready to. That?s the sort of real-time, continuous, cloud-connected thing we?re talking about here. Monica: Real-time optimization, and then you also mentioned the cloud virtualization part. What is that virtualization? How is virtualization in the cloud changing your solutions? Tom: Obviously, our solutions are becoming more connected, and you can expect that to continue in the future. We have a wide world of connection, at least electronically. Barriers are falling, as evidenced by this on-line interview. We?re many miles apart, and it?s working just fine. We expect this sort of collaboration in field tests to continue. After all, field tests naturally have experts in one location, and the man on the ground in a different location. As soon as you do that, electronic communication becomes just a natural solution. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |36| About Anritsu Anritsu Company is the United States subsidiary of Anritsu Corporation, a global provider of innovative communications test and measurement solutions for 120 years with offices throughout the world. Anritsu?s ?2020 VISION? philosophy engages customers as true partners to help develop wireless, optical, microwave/RF, and digital instruments, as well as operation support systems for R&D, manufacturing, installation, and maintenance applications. In addition to supporting precision microwave/RF components, optical devices, and high-speed electrical devices for communication products and systems, Anritsu provides a large portfolio of solutions to meet the growing demand for in-building wireless services from DAS to small cell environments. About Tom Elliott Tom has 20 years of experience in the telecomm industry working with RF and cellular technologies. Tom has concentrated on test and measurement for cellular base stations for much of this time. Tom is a Product Manager for Anritsu Company with worldwide responsibility for wireless service providers. He focuses on improving network performance and making technicians more productive through the technologies and tools of Anritsu. Tom has taught hundreds of technicians, written several procedures and courses, and regularly receives the input of technicians, managers, directors, and CTOs on new test requirements as the wireless network evolves. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |37| Profile Ascom Network Testing For more than 25 years, Ascom has helped mobile operators worldwide with testing, monitoring and optimizing solutions that span the entire wireless infrastructure ? from the core all the way to the RAN. In the RAN, densification has played an important role in shaping Ascom products over the years, but with the introduction of IP-based multi-RAT, multi- band and multi-layer networks, Ascom has developed solutions specifically targeted at operators deploying small cells, DAS and, more generally, HetNet architectures. Ascom?s TEMS? iBuildNet is a planning and design tool for HetNets which allows operators to design deployments that combine both indoor and outdoor infrastructure. It models multiple elements that affect performance, such as coverage, traffic steering, path loss, signal level, SINR, cell overlap areas, best-server maps, and LTE and Wi-Fi handover ? in 3D if desired ? to determine the required coverage in indoor locations. According to Ascom, TEMS iBuildNet can cut planning and design time by 50%. With TEMS? Pocket and TEMS? Pocket Remote, operators can measure indoor and pedestrian area traffic from handheld mobile devices. Specifically, these products can identify locations where performance differs from what the initial plan predicted, and can resolve the performance issues they identify. TEMS iBuildNet enables engineers to detect discrepancies between the real environment versus the plan, using the latest site survey information provided by TEMS iBuildNet Walk. With this solution, operators can collect data, and add text comments, video, photos and 3D models, as they deploy and test the networks. TEMS? Discovery also leverages data collected by TEMS Pocket or TEMS Pocket Remote to identify RF problems in the network, and geolocate their source. It allows for analytics and reporting in indoor testing, drive testing, and network diagnostics. Other solutions in the TEMS portfolio that focus on the RAN include: ? TEMS? Automatic, a tool for automated data collection for testing, monitoring, benchmarking, audit and verification, via probes that can be remotely controlled from a central location. ? TEMS? Investigation, for drive testing of the air interface and service quality. ? TEMS? MobileInsight, to test QoS from mobile devices, using QoS-specific KPIs, SLA monitoring, crowd sourcing, and subscriber feedback. ? TEMS? Monitor Master, to test and monitor network performance using simulated traffic at the application layer for different devices. ? TEMS? Symphony, for benchmarking. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |38| Ascom Testing and monitoring in densified networks A conversation with Todd Cotts, Product Marketing Manager, Ascom Network Testing Monica Paolini: My guest in today?s conversation is Todd Cotts, the Product Marketing Manager at Ascom Network Testing. Todd, can you tell us what Ascom is doing to support densification efforts? Todd Cotts: Ascom Network Testing has been around for several years. What we?re known for at Ascom Network Testing is our TEMS solutions: our TEMS products and TEMS services. For over a quarter of a century, we have been providing products and services in the network testing field to the telecommunications industry, including all of the top, tier-one US operators. Many of those services have been around the network testing area, but recently ? earlier this year ? we?ve launched a new solution that focuses on the design and deployment of small-cell and heterogeneous networks. Monica: With densification, there are many new challenges, but also wider opportunities for testing, because the role of testing is evolving. But before we get to this, we should define what densification is. Everybody?s talking about it, but are we all talking about the same thing? Todd: The way I look at densification is as a means by which a carrier goes about improving the capacity of its networks, especially in densely populated areas and large public venues. A lot of the capacity issues are driven by the demand of mobile users, especially data demand these days. As the data demand increases, the load is greater on the network. The capacity that operators originally planned the network to support is no longer sufficient. The traffic load is now straining the network. What happens is that the coverage begins to shrink when capacity is insufficient. People and calls are dropped off. The speed slows down. Latency becomes an issue. That?s really what densification is all about. And the way carriers are going about doing this is through small-cell deployments. Monica: How are operators addressing the capacity problem? Is the strategy the same across operators? Todd: The drivers are the same. Mobile-data traffic has increased exponentially and will continue to do so into 2020. Much of that mobile data traffic, 80% of it, is coming from indoors. A lot of it is from the commercial and enterprise segments. When it gets down to the drivers, there are a few things I want to iterate here. In 2015, for example, 15% of mobile data traffic was from social media, but, larger than that, 50% of it was from video. Video?s going to continue to be a huge driver. What it boils down to, Monica, is quality of experience. This is the whole purpose for a carrier to go into a partnership with an enterprise or a commercial segment. And a hotel wants to improve its customers? experience, and part of that experience is, of course, a mobile data connection, whether you come indoors or go outdoors. Carriers are focused on quality of experience. It?s been shown that the way customers evaluate their quality of experience is by speed. That?s one of the ways. Another one is video quality. We have all experienced stalling during the video. Another way to define quality of experience is the time required to download a web page on a mobile device. When the network is slow, it?s very frustrating. Then, you have the resolution of the video content, as well as the responsiveness of a mobile app. All of these things amount to one big, key driver, which is quality of experience. If you don?t get the quality of the experience right, whether you?re a carrier or an enterprise or commercial segment, whatever it is you?re doing, you?re going to churn. Tenants are going to leave your buildings. Hotel guests are not going to return. It?s a big thing for everybody, and everybody has a stake in it, not just the carriers. There?s also a near-future piece to this, if I may. We all talk about 2020. One of the near-future pieces of this is that, as I mentioned, video outstrips mobile data traffic, and it?s going to REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |39| continue to grow tenfold by 2020. In fact, there?s research that says about three-fourths of the mobile data traffic by 2020 is going to be video. That?s globally. There are some other challenges, we?ve got to realize, in the next four years. We don?t have a lot of time to do what we need to do ? improve quality of experience, expand the network, and improve capacity. Around the corner, you?ve got new mobile apps and services. You?ve got the internet of things. You also have smart cities. Smart cities are popping up everywhere. In the San Diego area, for example, a completely new urban development has popped out, and it?s all smart-city based, where all the digital devices are connected and talking to the internet, talking to one another. Then, we have the dense urbanization itself. As the urban populations continue to explode, and as smartphones and smart devices continue to be adopted, and as Wi-Fi and 4G continue to be used, you have this huge explosion of mobile data traffic demand on the network. If we?re not prepared to support that, through small-cell deployments, Wi-Fi offload, carrier Wi-Fi or other technologies, the quality of experience is going to go downhill. Monica: With IoT, we?re moving beyond subscribers? quality of experience. You typically do not have a human at the other end, but you do have many diverse requirements, and a huge number of devices. Todd: Gartner?s predicting, by 2020, 25 billion connected devices. That?s a lot of connected devices. Monica: Densification is often narrowly thought of as centered around small cells, but there are different ways to go about it ? and different technology solutions. Initially it was just small cells on lamp posts. Now, it?s much more than that. What are you hearing when you talk to operators? Todd: When you?re talking about densification, you?re really talking about small-cell deployments. But a small-cell deployment is anything other than a macro site. Small-cell deployments include many types of access nodes. Densification is also about indoor DAS, it?s about outdoor DAS. It?s about heterogeneous networks, which are really hybrid network solutions that combine multiple RAN technologies as well as multiple access node types, such as iDAS and oDAS. Wi-Fi?s a part of that, too. Not just enterprise Wi-Fi; we?re also talking about carrier Wi-Fi these days. And all of that is part of a small-cell deployment, depending on the need that?s been identified by the carrier. Monica: The networks are becoming more complex. In testing and monitoring, your work is becoming, also, more complex. How can you help mobile operators in dealing with the increase in complexity? Todd: At Ascom Network Testing, we have a number of solutions that help carriers densify their REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |40| networks. One of them is in just identifying the need itself. We have TEMS Pocket, for example, which is probably one of the most popular of our solutions for testing, but we also have TEMS Pocket Remote. With TEMS Pocket, I can go in and do a one-time test. I can either drive test, or do a site survey, indoors or outdoors. I can get an idea of how the network is performing at that moment in time, at that particular location, across those particular location parameters that I?ve defined. TEMS Pocket Remote comes into play here, probably more than even TEMS Pocket by itself, in that TEMS Pocket Remote is a stationary testing product. Basically, it?s an approach to testing the network over a period of time, at the same location. If I want to know, at any point in the city, or multiple points in the city, or multiple points indoors, or around the buildings, ?OK, how is the network performing over a period of time?? TEMS Pocket Remote would give me an idea of the capacity. It would also help me identify any not spots and any hot spots. Then I would match that with TEMS Discovery. TEMS Discovery allows me to analyze that data and look at it geospatially, and begin to identify where those areas exist and what type of events are taking place to cause the issues that we might have identified with TEMS Pocket. That?s the network testing piece. That?s where, at Ascom, we come into play. It?s really part of identifying the need. That?s where we?ve always played. We?ve played in identifying the need, identifying the problem areas. But with the launch of TEMS iBuildNet earlier this year, we?ve now stepped more into the game of not just testing to find out where the problems are and what the problems are, but now, ?How do we design a solution that addresses those problems?? TEMS iBuildNet is that solution. Monica: That is interesting, because a small-cell deployment is more complex than a macro-only, because you have the two layers: small-cell and macro-cell layers. From a testing point of view, it is a challenge, isn?t it? How do you deal with the increased complexity? Todd: TEMS Pocket and TEMS Discovery both allow us to look across multiple RATs at the same time. It?s not anymore just about testing; it is now about planning and designing the solution for the network, too. That has to be planned and designed based on what carriers need. When they go out and do the testing, they already have something in mind. They?ve identified problems, or they?ve had customers calling. Their network team has been identifying specific areas. But it?s when they can say, ?OK, these are the capacity targets that we want to achieve in these areas. These are the coverage holes that we have. These are the areas indoors and outdoors where we need to partner with the enterprises to make a better quality of experience for our subscribers and for their customers? ? that?s really the planning design part of it. That?s where TEMS iBuildNet comes into play and you can do that. You can do simultaneous multi-RAT design and simulations. Then, as a result, what you?ll have are simulation measurements. What we have actually found, Monica, is that with the automated simulation capabilities of TEMS iBuildNet, it has been proven to be within 5 dBm margin of error with actual network measurements once the solution?s been deployed. That?s critical, as well. It is important to make sure that you?re not overdoing your design, not overdoing your network. You don?t want to just throw an access node out there, or 10 or 15 of them, and say, ?Well, boom! This is, this is, uh, going to work!? Or a small cell on a lamppost when you may not need it on that lamppost. You may REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |41| need it on a park bench down the road, or on top of a building. That?s where the planning and design comes in, and with TEMS iBuildNet, it?s not just indoor. TEMS iBuildNet allows you to design hybrid indoor and outdoor, outdoor to indoor, or just indoor or just outdoor networks. Monica: These are all tradeoffs that operators have to make. You don?t want to use a lamppost if you don?t need it. Similarly, you want to understand whether it is indoor or outdoor capacity that you need. You offer a 360-degree approach, where you can plan, execute, and test. Todd: That?s it, exactly. Carriers don?t have money. When I?ve been out at trade shows with carriers and talking with them, the one thing I hear over and over from them, as well as from enterprises and commercial segments, is nobody has the money. Everybody?s strapped by budget constraints. With those budget constraints, who has time to figure out, ?Is it the right place -- is it the right time for the solution? Do I need a small cell, or do I need a DAS system? Do I need DAS, or do I need Wi-Fi, or do I need both? Where should I place them to make sure that my network is going to perform to the target expectations that I planned it to perform and meet those QoE expectations?? That?s what TEMS iBuildNet will do. Monica: Going back to the technology that we have for densification. There are some new developments out there, so it?s a moving target. There?s always new things that are happening. What do you see coming up that is relevant to our operators, and I guess, to you as well, if you choose to deal with it? Todd: LTE will continue to evolve, and obviously what we?re looking at whether there is a competition between the carrier and enterprise Wi-Fi. The Mobile Broadband Alliance is certainly concerned about the carriers entering into that 5 GHz space where Wi-Fi has played, and understandably so. Some of the solutions will be hybrid scenarios, where carrier Wi-Fi and enterprise Wi-Fi play nicely in the same sandbox. We have to certainly include that within not only how we test, but also how we design a network. That?s one of the future things. The other one is, of course, 5G is a big one. We?ve all heard about 5G. It?s on the horizon. Deployment is actually expected in that magic year 2020. There are some already out there, saying, ?Yeah, we?re deploying 5G, we?re testing it today,? or playing around with it. Until 5G settles down, we have to take a step back and say, ?OK, well, we?re just going to stay in the loop,? make sure that we?re connected to the carriers, make sure we?re connected to those driving the technology to advancements in the 5G arena, as well as the various associations and organizations that are driving all of that, like 3GPP. But between the LTE-U, the advanced Wi-Fi on the carrier side, and 5G in 2020, you?re also going to have cloud RAN. That?s something we also have to look at ? it is the virtualization of network capacity and the virtualization of networks within themselves. I?m excited about that, but those are all things that we have to factor in as our engineers, as our R&D department, continue to develop new solutions or advancements on solutions that we already have in place ? we have to take all of those things into consideration. Monica: It?s a challenge, because, as you say, 5G is not defined yet, but you need to test to make sure it performs as expected before launch. Todd: We want to encourage 5G, but we?re basically a supplier. Our main objective is to make sure that we?re partnering closely with, as I mentioned, the carriers themselves. What are their roadmaps? What?s going on with them? We?ve got to. I think that?s just good supplier relationships with your clients. It?s important to make sure that you?re listening to them. And you?re not just listening to them, but you also have people and teams, as we do, that are actually dedicated to the various organizations and the various initiatives, including heterogeneous networks. Their responsibility is to keep a finger on the pulse of what?s going on, what?s tested, where we are. We attend all the events ? we attend all the 5G expos, all the HetNet expos, CTIA. As part of that, we?re not just going to exhibit our wares, but it?s also to network with everybody else that?s in the industry, that?s driving a lot of these advancements. That?s what we are doing today. Monica: You were mentioning 2020 before, for 5G. You think that there?s going to be one date REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |42| when 5G will become commercial? I?m getting the impression that it?s going to be a lot of incremental changes. Todd: We all remember the 4G, when it came on board. There were a lot of carriers that said, ?Yeah, our network is 4G,? but it really wasn?t 4G, it was 3.5G. They called it 4G because it achieved 4G speeds. This is all about speed. Even 5G is all about speed, as well as efficiency. I agree completely with you. I think 5G is incremental; that?s why a lot of it?s going on. There?re a lot of people already saying that they?re launching it. In fact, they may be, but is it really going to be what?s finally called 5G? It?s very doubtful. We?ve got several more conversations across the various groups that define the advancements of the different technologies, not just small cells and those that are driving those technologies, but also DAS and Wi-Fi. It?s a big conversation that?s going on now, it?s going to continue to go on, and I think, to your point, we?ll see it little bit by little bit. Let?s keep in mind, 2020 is just four years away. Actually, less than four years. January 1, 2020, are we going to have 5G? Very doubtful that we?ll have the final version of 5G by that time. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |43| About Ascom Ascom Network Testing offers expertise and solutions that enable wireless operators to expand network capacity, improve operational efficiency and deliver a premier customer experience. Ascom develops its own line of mobile network testing, monitoring and post-processing solutions that have been trusted by mobile operators for decades under the TEMS? brand. Today, those solutions enable field testing (drive, in-building, autonomous) of mobile networks, automated post processing of data collected via these ? and other third- party ? probes, OSS-based network troubleshooting and optimization, and application testing and monitoring. About Todd Cotts Todd Cotts is part of the Product Team at Ascom Network Testing. Todd has over 15 years? experience in the telecommunications industry, having worked for some of the biggest names in the industry, including Sprint Nextel and Kyocera Communications. Having served in a number of strategic and leadership roles throughout the years, including directing product management of an indoor-outdoor network experience testing solution, and with an MBA in Marketing and near completion of a second Master?s degree (MS in Psychology with a Marketing focus), Todd brings to the table a multi-faceted approach to confronting many challenges faced by telecommunications professionals today. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |44| Profile CommScope CommScope offers a wide range of network infrastructure solutions that help operators and enterprises build, optimize and improve the efficiency of wireline and wireless networks. Its solutions target: ? Cellular and other wireless access networks ? Wireless and wireline fronthaul, backhaul and transport ? Cable networks ? Fiber optics networks ? Data centers ? IoT connectivity These solutions can be deployed both indoor and outdoor environments, ranging from stadiums and public transportation hubs, to medium-sized enterprise locations, to small-business and residential locations. In the mobile space, CommScope provides wireless operators with tools to improve network and spectrum utilization by boosting speed, capacity and coverage in the RAN and in the backhaul. In this context, densification is a key focus that CommScope addresses primarily with indoor DAS and outdoor DAS, small-cell backhaul and fronthaul, and cell-site solutions. The recent acquisitions of Airvana and the Broadband Network Solutions (BNS) businesses of TE Connectivity have broadened CommScope?s portfolio in densification. CommScope?s experience in DAS has focused both on indoor and outdoor installation. While the main focus for DAS is still on large venues such as stadiums, CommScope is expanding its solutions to make DAS more cost effective and easy to deploy in smaller venues. CommScope offers the OneCell system ? a hybrid small-cell solution that combines features from DAS, C-RAN and small cells to provide a scalable solution for indoor environments with demanding capacity and coverage requirements that uses the Ethernet existing infrastructure for backhaul. CommScope solutions include metro-cell concealment solutions for outdoor deployments. These are designed to address the challenges that mobile operators face in moving the telecom infrastructure from macro sites to DAS or small cells ? closer to the subscriber and in locations that are more visible, easier to access and difficult to protect. At the core of CommScope densification efforts is the company?s extensive experience in optimizing antenna performance to deal with increasing traffic density and the coverage requirements for voice and data services. CommScope invented remote electrical tilt (RET) solutions that allow operators to shape their antenna beams in real time. It also offers a Six-Sector Turnkey Solution that splits a single antenna beam into two, doubling the capacity, according to the company, without the need to install a second antenna. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |45| CommScope Building the foundations for densification A conversation with Ben Cardwell, Senior Vice President and Segment Leader, CommScope Mobility Solutions Monica Paolini: Our conversation on densification and RAN evolution at CommScope is with Ben Cardwell, the Senior Vice President and Segment Leader of CommScope Mobility Solutions. Ben, can you tell us what, in this context, you do at CommScope? Ben: As we all know, wireless networks will need roughly 1,000 times today?s capacity in 10 years. Operators generally have three tools they can use to increase the capacity of their network. The number one is to add more spectrum. This is very expensive, and the opportunity to get more spectrum only comes along every several years. Number two, they can make the spectrum they have operate more efficiently. Number three, they can densify the network, add more cells, and bring users as close as possible to a hot fiber hop-off point. The densification piece is key. That will be the number one way that you see this 1000X capacity come into the network over the next 10 years. At CommScope, we have been doing densification for operators for a long time. Densification is nothing new, but it will certainly accelerate. In the past, we have started with the macro towers, which are certainly the most efficient and economical way to start off for the operators. They?ve been sectorizing their sites, going from the traditional three-sector sites to six-sector sites or even more. We?ve been providing the tools and the know-how for them to do that. Once they get to that point and they?ve sectorized their macro sites, then they look to more in-building sites. In- building has for a long time been a key avenue to densification. Second, CommScope has been the largest provider of DAS systems in the marketplace over the last decade. We?ve deployed in countless public and private venues. The third thing we?ve done is working with neutral hosts and operators to deploy what we call oDAS networks, or outdoor DAS networks. oDAS can put loads of capacity on street corners and other outdoor locations in a very small footprint. Monica: What is it that you personally do at CommScope? Ben: In the sectorization of the macro towers, we provide high-performance antennas, filtering capabilities, and connectivity that allow operators to sectorize their sites. When you do that, you require some very finely tuned cell boundaries, eliminating interference. That?s one thing we do best. In the building space and the oDAS outdoor space, we provide the DAS equipment, and the design services, and sometimes even the deployment services to do that. Monica: As you said, densification is nothing new. It?s accelerating, but it?s always been there. It initially was more for coverage. Now it is more for capacity. Densification for capacity is different because the technology?s different, and because the needs are different. How do you see it changing, especially in the relationship between densifying the indoor versus the outdoor? Ben: It is changing. Operators will need to do both. They?ll need to cover more and more buildings from the inside out. In the past they have focused mostly on public-access venues ? big, big venues where lots of people go. Those have been done. Those are big buildings, big systems. Going forward, we will need to move into those second- and third-tier buildings that are more in the 200,000 to 500,000 sq ft size. These new systems will need to be much lower cost and be deployable by a different type of professional. Maybe an IT professional instead of an RF engineer with 15 years of experience. We?ve been focused on that in-building space, creating the platforms and the ecosystem to allow DAS to scale to a much larger audience. Also in that space we?ve been developing world-class indoor small-cell solutions. We have a solution called OneCell that provides a cloud-RAN approach to in-building, giving maximum capacity utilization in a building. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |46| In the outdoor space there will have to be many, many, many more of these small cells, especially in urban and semi-urban environments just to carry the traffic loads. There are three major problems that the operators have in this space. It?s getting power to the site, getting backhaul to the site, and most important, site acquisition. Site acquisition is becoming a major challenge. That?s something that, also, does not scale well in the industry, because it?s down to what the locality will allow. As we know, different regulatory or local approval councils have different requirements. We?re focused very much on creating solutions that allow scalability in this space. Monica: You raised many topics that I want to follow up on. Let?s start with the outdoors. You said that you?re trying to help operators address power, site acquisitions, and deployment. How can you help them? Ben: Site acquisition is, again, the number one challenge. It?s all about concealment and not creating an eyesore for the public. We are creating cabinets and concealment solutions that enclose small cells, antennas and all the infrastructure required for a small cell. Small cells may be placed either inside a pole, under a park bench, in something that may look like a vending machine ? something where it?s really disguised from the public. This becomes even more pronounced in the numerous historic districts in the US where you cannot see the equipment, you cannot see it at all. We?ve done several historic districts where we?ve replicated old-fashioned light poles that are from the early 20th century. There were gas lamps on the street, for example, to conceal the infrastructure inside and enable the fiber connectivity to the site with our fiber solutions, and even backup power in the sites for fail-safe operation. Monica: Today, the requirements from cities are highly varied. Do you think they?re going to converge at some point, that we?re going to have a consistent set of requirements across municipalities? Ben: I think there?s going to continue to be a large amount of customization, but the more of these cities and localities we deal with, through our partners, we are learning some of the commonalities. We are working very hard to create some solutions that will be a least common denominator, if you will, and more likely to be sited about various cities. The other key to this is we?re seeing operators and neutral hosts forming public/private partnerships with the likes of energy companies, or other utility companies, or the municipalities that actually own the poles. You?ll see in many cities that the poles and the infrastructure tend to be common throughout that city or municipality. We can create, oftentimes, REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |47| two or three solutions that we can get approved and deploy in those locations. Monica: What is the relevance of the system integrators in all this? Ben: At CommScope, we typically design and manufacture the infrastructure to make this happen. The integrators play an absolutely key role. The local integrators tend to know their environment very well. Of course, there are some national operators in various countries, and integrators that understand the whole ecosystem. Generally, the local integrators play a key role because they have worked in that environment before, either providing the solutions to the utility companies or for the municipality. They?re very important as part of the ecosystem. Monica: Do you think they?re going to play a more important role than operators themselves in doing the installations? Ben: In doing the installations, absolutely. Because of the scale and the number of small cells or densification points, whatever type they may take on or that are required, operators are not going to be able to do this all themselves. They?re not going to have that scale with their own resources. They?re going to have to rely on local partnerships and even some regional partnerships to get it done. Monica: You mentioned both oDAS and small cells for outdoors. What are the pros and cons of each solution? Ben: They both have pros and cons. Really, it?s about the specific task at that specific site. Again, operators will need multiple tools in their basket of tricks to do all the sites that are required. The advantage of oDAS is that you can bring loads of capacity into a very small form factor. You can feed it with fiber. You can feed multiple operators. You can feed multiple frequency bands to that one radiating point, a very small form factor that can be hidden. This is the advantage of oDAS, if you don?t need that much capacity at a particular site. You only need a few channels or a single operator; then a small cell or a remote radio head, a miniaturized remote radio head, can be a very good solution. Really, it?s all about looking at the economics for the task at hand. Monica: You want to have multiple tools to address the requirements. We have powerful DAS for stadiums. If we go indoors, obviously that solution is not relevant for a small office. How can you get DAS to adapt to the smaller venues? What are the tradeoffs between a DAS, even a DAS for a small office or venue, versus small cells? Ben: We believe that DAS will continue to be the tool of choice for the large public access venues and sporting stadiums, airports, the big high-rises, big shopping malls, things of that nature, where every operator is going to want to be on that system. They?re going to have to provide every bit of spectrum they?ve got into those venues. As we get to the smaller venues, we need new tools. Again, in these smaller venues sometimes we?ve been involved in DAS, obviously. The newer DAS solutions that we have are planned, installed, commissioned, and operated just like any other piece of IT infrastructure. We can enable an IT organization, an enterprise, to use those. Those would still be an economical, small, mini-DAS solution, if you will, where you need multiple treatments of bands, or more than one operator. In a building like corporate headquarters, where the enterprise may be standardized on a single operator, all they need is one operator in the building, and maybe one or two bands. Then a small cell starts to make more sense. Those solutions, also, are becoming more enterprise friendly because, to get in-building infrastructure to scale, you?ve got to tap into that enterprise ecosystem. Monica: I guess there are in-between solutions, where you have a C-RAN approach. Do you consider DAS to be a type of C-RAN? Your OneCell approach seems to be a hybrid of small cell and DAS, with a C-RAN architecture. Ben: The OneCell system uses what you might call a hybrid approach. It?s not a stand-alone small cell. It?s a collection of access points within a building to form a C-RAN. We call this a managed C-RAN solution, an intelligent small-cell solution. With OneCell, you have a system that operates in a closed environment inside of a building, with the backhaul to the operator, that can be deployed extremely cost effectively. Monica: What kind of a backhaul do you use for the in-building connectivity? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |48| Ben: It?s IP backhaul, but it would still go out and leave the building on the fiber. Monica: Fiber from the building, and then is it Ethernet within the building? Ben: Within the building it?s generally your standard twisted pair, Cat 5 or Cat 6 cable that is already in that building. Monica: Operators are looking more and more into using unlicensed bands. They?re doing that already with Wi-Fi, but also they are looking at LTE unlicensed ? LTE-U, LAA, MulteFire. What are you seeing or what are you doing on that front? Ben: We believe that those unlicensed bands will be very important, because spectrum is one of the most valuable assets. Using that unlicensed band will be key. We believe that this signaling, the part of the network that controls the call, will always be in the licensed band, because the carrier needs to control that very carefully. The newer technologies, like LAA or LWA, will allow the LTE protocol to take advantage of some of that unlicensed spectrum, grab it, use it while it?s available, and be able to ramp up and down the use of that dynamically. We think that?s going to be very key to have that kind of on-demand use of unlicensed spectrum. When you do that, it adds to the complexity of the RF network. Our expertise at CommScope is managing that RF interference. We believe we?re the best there is at understanding and mitigating the interference in the RF layer of the network to make all those bands work together efficiently. We would be creating DAS solutions in antennas and on connectivity infrastructure to minimize all the interference in the building. In the outdoor space, the same thing. We?d be working to create the antennas and filtering solutions to make that sufficient. Monica: That?s interesting, because interference is nothing new, but for a mobile operator to manage interference in an unlicensed band, or to manage capacity, for that matter, in an unlicensed band is an entirely new endeavor. Ben: You?re exactly right. Monica: Many operators are a little bit nervous about how to do it, because still they have their licensed band as an anchor, but there are still a lot of challenges there. What are you hearing from operators? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |49| Obviously, interference in an unlicensed band is something you can manage only to some extent. It depends on what else is going on at the same time. Ben: That?s correct. Interference has become a much more serious and pointed issue now that LTE has been deployed. In spread-spectrum systems like LTE, and even in CDMA and in UMTS, as we move up in the G cycle ? 2G, 3G, 4G ? interference becomes more and more important. One reason is that the traffic on the network is getting higher. The number two reason is that you?re trying to get more and more speed out of this fixed-frequency resource. You?ve got to fine tune and clean up that spectrum as best as we can. Every antenna?s got to have a very clean, targeted pattern covering the areas, not overlapping with its neighbor. We?re managing that type of interference plus just the normal interference that can come from the environment of operating a mobile network. We?re creating products that are easy to install, that work well together so that ? even in the interface points between the different pieces of equipment in the network ? you are not creating opportunities for an installer to create interference when he connects them together. Monica: As you say, one other crucial thing, as you move indoors especially, is that you need to be friendly to the enterprise. They need to be able to easily fix problems if there is something wrong, or to have an integrator come in. How do you see the role of the enterprise in all this changing? Are they going to be more involved? Are they going to pay for infrastructures themselves? How is that going to work out? Ben: This is a very good question. That is extremely important, that we enable that enterprise ecosystem to be somewhat self-sufficient. The carrier is going to always have to play a key role, because it?s the carrier?s licensed spectrum we?re talking about. They will always have to be comfortable with whatever is radiating on their spectrum. At the end of the day, it?s their customers. If my cell phone doesn?t work, I?m going to call my operator and be the one that complains. We?re working very hard to create the products that are friendly to the enterprise but acceptable to the operator. More importantly, we create products that are extremely simple to design, deploy, and install, so that the much larger market of IT engineers who are going to be installing them are comfortable working with them and can install them reliably. It?s not just about the IT people in the building. It?s about the ecosystem that feeds them today. We have to enable that ecosystem because, again, we?ve got to scale to not just doing the thousands of buildings a year that are done today with DAS. We?ve got to scale this to tens of thousands or even to hundreds of thousands a year of buildings that can be deployed. We believe there?s five billion sq ft of opportunity out there, of uncovered commercial space out there that needs to be covered. The only way we?re going to do that is by enabling an ecosystem. We?re working very hard at that. Monica: Yes, absolutely. Scalability is crucial here. One other trend is virtualization. Is virtualization going to help scalability? Ben: It will help scalability. It will definitely help improve the ability to deliver 5G services. It?s a journey to virtualization for the operators. They?re starting with some very simple things, like centralizing the baseband in the network. Today, in most cell sites the baseband is sitting at the bottom of every tower, dedicated to that tower. Sometimes it?s heavily utilized. Sometimes it?s not utilized. If you take a cluster of 50 sites, and take that baseband away, move it to a centralized point, you can make it available to all those 50 cell sites dynamically. When there?s a football game going over here, you can shift all the traffic over there. If it?s rush hour and a traffic jam, you can shift it all over here. We see that starting to happen already today. That?s step number one. The next step would be, from a capacity perspective, virtualizing that. Moving it further back in the network and putting it on software- based servers. That can even be made available dynamically to larger chunks of the network. We think this is a migration that will happen over the next five years as people prepare for a barrage of new traffic. Monica: What are you working on at CommScope right now to meet the challenges over the, say, next five years? Ben: At CommScope we have two key technologies that are going to be the REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |50| fundamentals of the 5G network. In the next generation, network broadband and wireless networks will converge, and customers won?t be able to tell, and won?t care, whether they are on a fixed network or a wireless network. They?ll get the same type of service from both. We believe that wireless and fiber are going to be the two big enablers of that converged network. We are the leaders in both in the layer of the network that we operate. We?re creating solutions that are going to drive this centralized C-RAN and virtualized RAN (or vRAN) network. There?s going to be a lot of fiber in these networks. Very few people know how to manage fiber and wireless as well as we do, as it relates to a wireless network. Then, at the very network edge, at that wireless access layer, we are working with our industry partners to create the same types of infrastructure we have in the past. Smarter antennas, where they have more intelligence in them. Things like massive densification will become a big play where you have beamforming, because beamforming helps further reduce that interference in the network. On the in-building front, designing the next- generation DAS systems and small-cell solutions that scale to that enterprise ecosystem we?re talking about ? we think that?s a big opportunity that?s largely untapped out there. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |51| About CommScope CommScope helps companies around the world design, build and manage their wired and wireless networks. Its vast portfolio of network infrastructure includes some of the world?s most robust and innovative wireless and fiber optic solutions. Its talented and experienced global team is driven to help customers increase bandwidth; maximize existing capacity; improve network performance and availability; increase energy efficiency; and simplify technology migration. You will find CommScope solutions in the largest buildings, venues and outdoor spaces; in data centers and buildings of all shapes, sizes and complexity; at wireless cell sites; in telecom central offices and cable headends; in FTTx deployments; and in airports, trains, and tunnels. Vital networks around the world run on CommScope solutions. About Ben Cardwell Ben Cardwell is Senior Vice President of Mobility Solutions at CommScope. He is responsible for leading the global business unit that develops innovative wireless solutions for use in service provider and business enterprise networks around the world. Prior to his current role, Ben was senior Vice President of Global Wireless sales, responsible for leading all of CommScope?s customer-facing activities for the wireless group globally. A 25-year veteran of the telecommunications industry, Mr. Cardwell also served as Vice President of Wireless Sales for CommScope Asia Pacific, where he worked closely with US and Asia Pacific service providers in developing and deploying radio frequency and data communications infrastructure for voice and data services over mobile networks. Prior to joining CommScope, Mr. Cardwell served in various leadership positions in research and development, product management, systems engineering, and field sales with UTStarcom, Ericsson, and 3Com. Mr. Cardwell graduated from Davidson College in North Carolina with a bachelor of science degree in physics. He holds an MBA from Kellogg Graduate School of Management, Northwestern University. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |52| Profile InterDigital Since 1972, InterDigital has developed a wide array of new technologies and contributed to establishing wireless standards across cellular and IEEE 802-based technologies, with a strong focus on Wi-Fi. Complementary to its work on wireless, InterDigital has developed IoT solutions for the transportation, automation (e.g., sensors, remote control), healthcare and industrial verticals. In this area, InterDigital has launched, an operating environment that facilitates the development and launch of IoT applications in which multiple ecosystem players, platforms and interfaces interact. The oneMPOWER? platform also supports growth in IoT by providing tools to manage devices across verticals, applications and form factors. In wireless, InterDigital focuses on three solutions, all supporting the densification trend among mobile operators: ? EdgeHaul?, a low-cost, high-capacity, millimeter-wave transport system in the 60 GHz band, which can provide mesh backhaul in small-cell and carrier Wi-Fi deployments. EdgeHaul can also be used for residential fixed-wireless broadband access. Low latency, support for network slicing, and SDN support make EdgeHaul a platform well suited to 5G deployments. The low latency and high capacity make EdgeHaul a solution that can be used for fronthaul in C-RAN deployments. ? Ultra Mobile Broadband, a 5G access platform being developed to bring high capacity and low latency to mobile networks that use frequencies above 6 GHz. Ultra Mobile Broadband leverages new spectrum allocations in the millimeter-wave bands, and it can target outdoor hotspots and indoor environments, as well as provide in-band backhaul. It supports both MIMO and multi- user MIMO (through hybrid beamforming) in TDD spectrum. Because of the short range of millimeter-wave technologies, deployments will target high-density locations, such as bus stops, central-city streets, parks, malls or airports, or specific events, such as marathons and other sports events, political conventions, or other public gatherings. ? Next Generation Networks Platform, a flexible routing solution to increase efficiency in transmission and optimize video performance, leveraging NFV/SDN, MEC and ICN. The platform is a hybrid approach that combines features of IP and ICN. It uses multicasting to increase network utilization and resiliency and to reduce latency. In a move away from host-to-host centralized processing, this approach pushes content and functionality toward the edge, closer to subscribers. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |53| InterDigital Densification in millimeter-wave bands A conversation with Alpaslan Demir, Principal Engineer, InterDigital Monica Paolini: Our conversation with InterDigital about densification and the evolution of the RAN is with Alpaslan Demir, a Principal Engineer there. Alpaslan, could you give us an introduction on what InterDigital is doing on densification and what you?ve been working on, on that topic? Alpaslan Demir: InterDigital is a multifront company for many research topics. One of the topics we are heavily involved with is densification. We support multiple projects in the densification domain. I?m part of the team who is looking at the next- generation millimeter-wave network. We look into the challenging problems in densification and work on creating solutions. When we talk about densification, we talk about ultra-dense networks in general. Monica: There are different ways to go about densification. Operators are pursuing many different roads to get to a massively densified network. One way is to look at new bands. Alpaslan: In the 5G domain, we distinguish between bands below-6 GHz and above-6 GHz. The primary focus in my team is on bands above-6 GHz. Above 6 GHz deployments are in the millimeter-wave bands. Some people refer to bands above-6 GHz as centimeter-wave and millimeter-wave bands. We are talking about frequencies in the 28 GHz or 39 GHz range. We?re talking about spectrum in the 60 GHz or 70 GHz as well. The beauty of these frequencies is that the new bandwidth they make available is tremendously large. You are talking about Mbps or multiples of- 100 Mbps bandwidths, with up to 2 GHz bandwidths, or multiples of 2 GHz, especially at 70 GHz. This gives you the ability to increase densification. The more bandwidth you have, the more data you can transmit. When it comes to the millimeter-wave domain, one thing we need to understand is that, due to the propagation loss, you need to deploy nodes very closely. Maybe you?re talking about spacing nodes at 50 m to 100 m to 200 m. This automatically creates densification. When you look at the bandwidth in terms of Mbps per hertz, the concept of areal densification comes in. With the addition of millimeter-wave bands in densification, the definition of capacity should not be limited to bps/Hz but it should involve space as another dimension. For example, if there are 50 links deployed over one sq km, each with 10 Gbps over 2 GHz channel bandwidth, then the total capacity can be defined as 500 Gbps/sq km. Monica: The need to have a denser network is a challenge in millimeter-wave bands. It?s a limitation compared to the below-5 GHz cellular spectrum bands, where you have much wider reach. But it?s also an advantage, because it reduces interference. It?s a tradeoff there, because you can reuse spectrum more regularly than you can, for instance, in the 700 MHz bands. Alpaslan: Yeah, definitely. When you look into millimeter-wave bands, you need highly directional antenna systems. With the highly directional antenna systems, people think that you definitely suppress the interference. However, that?s not very accurate. Overall, you can reduce the interference. You still have interference issues with highly directional beams. Monica: What kind of deployment scenarios do you see for these millimeter waves? Alpaslan: You definitely can talk about indoor and even outdoor scenarios, urban environments, definitely ? wherever you need very high density, you can utilize the millimeter-wave network. Campuses, enterprises, malls, all sorts of locations can definitely utilize millimeter-wave applications. Monica: You mentioned 5G. We?re seeing a trend towards some of the elements of 5G becoming available before true 5G is deployed. Do you think this is the case? If so, what is the timeline? Do we need to wait for 5G to be completed, or can we get started ahead of 5G full definition, with gradual changes within 4G? Alpaslan: That?s a very good question. In a 5G domain, certain technologies are developed and certain prototypes are available. However, when you look into the ecosystem, you do not see commercially viable formats yet. Especially in the RF domain, the antenna structures, solutions to REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |54| merge the antenna with the RF chain are not yet commercially available. This is delaying things. The other aspect is the standardization process. As they did in the 3G and the 4G domains before, now companies have started looking into the standardization aspects of 5G. A reasonable time everybody is talking about for commercially viable deployments in the 5G domain is 2020. Monica: Before that, before we get to 2020, what do you think is going to happen in terms of densification? Alpaslan: There will be prototypes, there will be a ton of research, and the testing and the capabilities are going to come up with densification. In Europe, there are several research facilities or places where the deployment scenarios are being tested. In the United States, we are expecting similar activity. The FCC is making new spectrum bands available in which we can start testing and deploying our prototypes. Monica: In terms of regulation and band availability, do you expect to have millimeter-wave bands that are available worldwide or in most markets? Alpaslan: It?s very difficult to achieve a global synchronization on these bands, and everybody knows that. For instance, the 28 GHz band will become open in the United States, but you may not have the same band all over the world. That?s a challenge. As engineers, we are definitely up for the challenges, and we?ll find solutions to accommodate whatever the needs are in this domain. Monica: What about the standardization process you mentioned? 3GPP is working on this, and there is a lot of research going on. Do you expect it to be polarized, or is the industry converging nicely on new standards? Alpaslan: There are always some glitches here and there. However, when you look into how 3G panned out, and 4G similarly, I personally don?t see much of a problem converging on 5G-domain solutions. But 5G is not just a single concept that fits everything. 5G has many facets. We?re talking about low-latency applications, such as those for tactile internet. We are talking about high- throughput applications. And there are many additional aspects. Even IoT concepts are panning out as part of 5G. The 5G is much, much greater than 4G and 3G. But we definitely need to have consensus. Monica: IoT is a driver to 5G and also benefits from it. How important to do you think IoT is as a driver for densification? Alpaslan: My answer may be a little bit technical here. In normal densification, the concept of fiber REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |55| drops for a dense network may become an issue. With respect to the number of fiber drops in the system, how could you reduce this number of fiber drops? Let?s say that instead of using fiber drops in every node, you can connect these nodes with wireless backhaul. You can obviously increase the number of hops doing that, but the main benefit is the total cost of the deployment. The backhaul network that you create will be wireless. However, due to the multiple hops that you introduce, there are latency problems that you have to solve. From any standardization perspective, the standard has to be cognizant of all these scenarios and find a common ground, so that it empowers people to use their own applications and interpretations, and it creates harmony. Monica: Because there is so much spectrum in the millimeter-wave bands, can you use the same band for both backhaul and access? Alpaslan: Yes. One of the approaches we take at InterDigital is that we?ll have these two GHz links available to you. Not always do you need the backhaul links utilizing these bands. In our approach, we?ll definitely look into the joint access and backhaul concepts. Where we deal with interference management, you do have interference from the backhaul to the access or from access to the backhaul. On top of this, you have latency issues that you have to fix. We look at densification holistically, and enable the joint-access backhaul, and solve many problems coming with it. Monica: Can you tell us something about how you manage interference? Alpaslan: One simple example I can highlight is that, if you have multiple channels available to you between neighboring nodes, you can definitely set these nodes using a different channel, such that the neighbors will not see each other?s signals and the impact of interference from the second-tier neighbors will be lower. When you are doing this, you have to be very careful about your system?s performance, the radio performance, and the leakage that may come from other channels. Another example is that interference metrics knowledge of the directionality of interfering links allow you to create a dynamic routing setup to mitigate interference. You can even create different directions. Instead of going through a hop directly, you can use multiple hops to convey your information, so that you don?t interfere. This is basically with one link active. The one link is no REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |56| longer affecting the other link if you start playing with the directionality of the links. Monica: If you have multiple hops, latency may become an issue, and latency is a crucial factor in defining performance. You need not only capacity, but low latency to get a good quality of experience. In 5G, that?s going to be a major requirement. How can you achieve these lower latencies? Alpaslan: We do have many other ways of solving this problem. One simple example, again, is with multi-hub systems. You are receiving packets. Normally, what you do is you absorb all the packets, and once you have received everything in that packet, you start forwarding. If the packet is causing you 10 units of delay, now you have to wait for 10 units, and then start forwarding that same packet of 10 units to the next tower. What you can do is create much smaller units within that packet, and start sending these small units without waiting for the entire 10 units coming in. Let?s say you start transmitting every unit without waiting. You immediately reduce your latency by doing this. Monica: In addition, with the increased complexity in the RAN, there is much more work that we all need to do in order to make sure the performance is high. However, inevitably, as you move to 5G, you?re moving to an environment where there are multiple wireless interfaces used for coverage, capacity, or both. You need to integrate them all. What?s your view on what?s the best way to go about it? Alpaslan: I definitely see legacy devices as an integral part of moving forward. We cannot just forget about legacy devices and the legacy infrastructure, and then start building completely brand new 5G infrastructure. We need to develop technologies that take advantage of existing legacy infrastructure, as well as of the opportunities created by the bandwidth, the latency, and such of the 5G domain. In the 5G domain, the systems are heavily populated, and highly directional beams are utilized. But you cannot have coverage in every corner. Even your hand movements or gestures on your handset will completely destroy your link, and you may lose connectivity. What are you going to do if that?s the case? Your system has to be adaptable enough to go back to the legacy network and start using it. Wherever it makes sense, we should look for solutions that aggregate both the 5G and the legacy systems. Monica: 5G, 4G, 3G, they need to be integrated tightly, so that you can have devices working back and forth among interfaces. Wi-Fi?s part of the picture, too, right? Alpaslan: Wi-Fi is always part of the picture. As a matter of fact, Wi-Fi standards are adopted much faster than 3GPP standards, because the focus is more narrow and the scope of standardization more limited. When you look at the 5G domain within the 3GPP perspective and, more generally, at the evolution of the cellular domain, the industry is much larger than the Wi-Fi industry. It takes longer to converge and implement new standards. InterDigital has resources working in both directions, cellular and Wi-Fi. Monica: When I talk to them about higher frequencies, they?re still a little bit nervous. They?re much more familiar with the lower frequencies, where they have full control and have fully licensed bands with good penetration and wide coverage. As you move to higher frequencies, the regulation is different, coverage is different. What are you hearing from them? Alpaslan: Let me state this: there is no escape from creating solutions for millimeter-wave or high-frequency bands. The overall industry is pushing for that. We definitely see some operators taking advantage of that, as well. Even today, we talk about operators embracing Wi-Fi and connecting with Wi-Fi, and we do see a lot of ways to merge LTE and Wi-Fi systems. Moving forward, the anticipation is that some of the bands on the millimeter wave could be licensed, or could be semi-licensed, and some of the bands, like 60 GHz US ISM band, could be unlicensed. From an operator perspective, it is best if you can take advantage of what is out there. The operators should be more adamant about creating solutions. Some of the applications in 4G were unforeseen. When 4G was enabled, then these applications popped up. With 5G, what we have is a tremendously large bandwidth, a very fast network, and all these REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |57| capabilities. A ton of new applications that would be mind- boggling would come up. We will see. Monica: It will be interesting to see. There?s a lot of work ahead. If you look at the next five years, what is InterDigital focusing mostly on? Alpaslan: For the densification purposes, we will continue to look into the solution space and solving the challenging problems. I see InterDigital providing solutions, helping to shape the industry, contributing to the standardization process, and introducing products, as well. We will do this not only for 5G, but for what comes after 5G. Monica: 6G? Alpaslan: 6G, hopefully. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |58| About InterDigital InterDigital, Inc. designs and develops advanced technologies that enable and enhance mobile communications and capabilities. Since its founding in 1972, its engineers have designed and developed a wide range of innovations that are used in digital cellular and wireless products and networks, including 2G, 3G, 4G and IEEE 802-related products and networks. For over four decades, InterDigital has been a pioneer in mobile technology and a key contributor to global wireless standards. InterDigital?s team of more than 170 engineers ? approximately 80% of whom hold advanced degrees, including over 50 PhDs ? has unparalleled expertise in major mobile connectivity and content delivery technologies. Since 2000, InterDigital has spent over $1 billion on technology research and development. InterDigital is a registered trademark of InterDigital, Inc. EdgeHaul, oneMPOWER and are trademarks of InterDigital, Inc. About Alpaslan Demir Alpaslan Demir is a Principal Engineer in the Future Wireless Group at InterDigital. He is part of a team working on NextGen Millimeter-Wave Architectures and currently focusing on activities related to millimeter-wave densification. He has been serving the wireless communications industry for more than twenty years with a unique combination of experiences relevant to MAC, PHY, and RF design. Notably, he is a prolific inventor with 56 granted and numerous pending patent applications to date. He is an IEEE member and holds a Ph.D. degree in Communications from Polytechnic Institute of NYU. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |59| Profile Kathrein Founded in 1919 and headquartered in Germany, Kathrein is a leading vendor of antennas and related equipment, such as filters, combiners and concealment solutions, for wireless networks and for multiple verticals. Transportation is a vertical in which Kathrein has a strong presence, with antennas and other components for the railway and automotive industries. The company is leveraging its expertise in this area to enter the IoT market and, more specifically, to provide connected car solutions. Industrial automation, logistics and retail are other IoT core verticals to Kathrein. Kathrein also provides antennas for indoor connectivity of private networks in enterprise, hospitality and other venues. Those solutions can be used for content delivery (especially video) and other data services, as well as in satellite communications and broadcast. Cellular networks, however, are the largest segment at Kathrein. The company offers a wide range of solutions for indoor and outdoor coverage, targeting different network layers ? from macro cells to small cells and to DAS. To support operators?, need to boost coverage and capacity, Kathrein has developed multiple solutions that enable densification. The most recent is Kathrein Street Connect?, a small-cell antenna system in which antennas are located just below street level, accessible through a manhole cover?type lid. By placing antennas and BTSs below street level, operators can deploy unseen infrastructure that meets municipalities? requirements more easily, and can have easier access to backhaul and power, than other outdoor equipment. Kathrein offers antennas for above-ground small cells, as well. These are designed to operate in the increasingly complex networks that result from the growing adoption of small cells and need to accommodate higher and more diverse traffic loads. And Kathrein continues to optimize them to meet increasingly stringent requirements in terms of, for example, regulation power levels, provisioning, operations, antenna visibility, RF exposure, and ease of installation. One area that is growing in relevance to densification is antenna concealment. Alongside macro-antenna concealment solutions for urban and rural environments, Kathrein provides ways to embed antennas into a variety of street-furniture elements. Kathrein Inside Connect, for instance, was developed in collaboration with JCDecaux to provide a modular antenna that can be integrated into advertisement infrastructure (e.g., billboards and bus stop shelters). For indoor environments, Kathrein offers DAS and small-cell solutions for different types of building structures and traffic patterns. In this area, Kathrein has recently introduced K-BOW, a micro C-RAN system, in which antennas are connected to a shared baseband, typically located within the building. K-BOW supports multiple mobile access frequency bands from 700 MHz to 2.7 GHz, including LTE-A and Wi-Fi. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |60| Kathrein Making densification equipment go unnoticed A conversation with Jim DeKoekkoek, Product Line Manager, Antennas and Small Cells, Kathrein Monica Paolini: This conversation on the densification of RAN and its evolution is with Jim DeKoekkoek, Product Line Manager for Antennas and Small Cells at Kathrein. Jim, could you tell us what you personally do at Kathrein, and what Kathrein is doing in the area of densification? Jim: My role here is one of being the interface between our engineering department and the market. As part of that, it really is a good chance for me to visit with customers, find out what their needs are, where they?re going, what the directions are ? and coordinate that with our engineering folks, who are largely based in Rosenheim, Germany. At Kathrein USA we had big changes in the last couple of years. We recognize that in a competitive business, Kathrein really needs to become a player in the US more than it has been. We?ve made major strides that way, and relocated our office to the heart of the Telecom Corridor? in Richardson, Texas. We recently closed a manufacturing plant in Oregon, opened a huge new facility in Mexico, centralized our warehousing in Texas, and become more involved with industry working groups such as 5G Americas and IWPC. Monica: But the company is based in Germany, with clients worldwide. Jim: Exactly. One of our challenges, in the past, was that we were more Eurocentric than we really wanted to be. We recognize that the US is a strong market for us and have taken some big steps to realize the strong opportunities here. The Kathrein name means a lot to people. The quality is excellent. It?s an enjoyable company to work for, for those reasons. Monica: When we talk about densification, there are many ways to go about it. Operators will, of course, pursue multiple paths at the same time. But these days when I think about Kathrein, the first thing that comes to mind is Street Connect?. This is a novel approach to densification. Jim: Street Connect has been a lot of fun for us. We were contacted originally by an operator in Switzerland, by the name of Swisscom. They had done quite a bit of evaluation of costs related to deploying small cells. They had the typical problem where the data usage is going sky high. They said that, since 2008, it had gone up a hundred times. They have very strict zoning standards in Switzerland and therefore difficult to deploy. They were looking at ?where can we install antennas for small cells in new and novel places?? They actually came up with the concept of installing it in the ground, in what looked like manhole covers. They looked at a few antenna vendors and ultimately chose Kathrein to bring the solution to market due to the high level of quality and engineering expertise. We did some joint development, and 17 trials in and around Switzerland to determine performance and coverage capabilities. Voila, we have this amazing product now that provides a solution zoning and aesthetic challenges all mobile operators face. Monica: You said that they look like manholes, but they?re not. What?s the difference? Jim: The average person walking by can?t tell the difference. The cover, of course, is not metal, like a normal manhole cover as that would cause interference, but it is a metal-looking composite cover. It?s designed and tested to withstand up to 40 tons so it can handle heavy trucks and traffic. Monica: What if you were to put them in a manhole itself? Obviously, you?d probably have propagation issues with the metal of the cover, but does it have to be in a different area? Jim: It does need to be in its own separate enclosure. We don?t want to restrict access to an actual cover, where there actually might be a need for workers to go into that. Also, it?s smaller in diameter. It?s about 17? inches in diameter, which actually is too small for most people to get into. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |61| Monica: Usually what you do when you go from macro to small cells, you go from way up high, and you get progressively closer to the subscriber. Kathrein goes one step further, because Street Connect goes below the subscriber. What does that do in terms of the interference, say, with the macro, when you have a co-channel deployment where the macro and the small cell use the same spectrum? Jim: Placement is really key there, to try to prevent that interference. If you?re designing a system, you?re going to look at maybe trying to shield from the macro cell using surrounding buildings. Part of the coverage of this system really depends on reflection. It?s commonly located adjacent to buildings, where we actually get good multipath, and good coverage that way. Monica: In terms of cost, how does Street Connect compare to a lamppost or other outdoor small-cell deployment? Jim: Swisscom compared Street Connect to, first, macro cells, and then to conventional small cells on lampposts and so forth, over a five-year period, to calculate all their maintenance costs, and the installation of fiber. Swisscom found that it comes out to be about half. It was very attractive from a perspective of cost. Really, that is the main driver here. Certainly, they?re going to use other tools as well, where it makes sense. I?m sure they?re going to still continue, as any operator would, with lampposts, and other types of small cells. But this really worked well from a cost perspective. Monica: If fiber is available, it?s easier to have to the small cell underground than if you go to a lamppost, where fiber connectivity is usually a problem. Jim: Exactly. Monica: Swisscom must have been talking to cities and municipalities. Were they open to this type of deployment? Streets are under the control of municipalities, and so you need their support? Jim: Absolutely. The right-of-way for locations for the Street Connect is a big deal. Zoning and placement of antennas, particularly in big cities ? where you have this huge, dense traffic load requirement ? is a big problem. One of the fun parts of the Street Connect is that we have cities that actually are interested in deploying it and that have control of the right-of- way. We have customers who will advocate for it and streamline that zoning process. Monica: Small cells represent a new approach to wireless deployments. We are trying to put the telecoms infrastructure in a place where, traditionally, there was none. Are there other places? You?re not just deploying small cells underground. Where else will your products go in the future? Jim: There?re a lot of tools in our toolbox. That?s an old clich?, one of our most popular to date for neutral host and mobile operators is our canister small cell product line. That?s one area, and we?re constantly innovating and enhancing those. by adding features and capability ? extended frequency ranges as new frequencies, such as the REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |62| 3.5 GHz and the 5.8 GHz, start to come into play. A lot of demand for that. The other thing is that most of the small cells have been 2x2 MIMO. Traditionally, that?s been adequate for most capacity requirements. But we?re starting to see that in major cities, where they don?t have any more capacity or place to put another antenna that 4x4 MIMO is becoming a reality, to get the capacity they need. We?re adding the 4x4 MIMO. Another approach in terms of antennas, both new and existing, is working with third-party firms to come up with flexible mounting and concealment options. We have an antenna that we call a smart-pipe antenna, internally we smilingly call it the barber- pole antenna, because that?s what it looks like. That antenna can be mounted on, say, the corner of a building. What?s cool about it is that the antennas can be rotated, and this way you can customize the direction of coverage. An operator can have this antenna on the corner of a building, in a downtown canyon environment, and aim one antenna to the north, and the other antenna to the west. Another thing I can do with that antenna option is to mount it like a paper towel roll, meaning that it?s horizontal. Mounted on the side of a building, an operator can aim one antenna at the lower floors, and one antenna at the higher floors. Another creative solution that we?ve had fun with is to mount the smart-pipe on what they call the messenger wire -- the strand cables that run between telephone poles. We have a kit to mount the antenna hanging from the wire and next to a radio. We can accommodate 2x2 or 4x4 MIMO with it. Again, we can adjust where the beams go. Those are the kinds of things we?re doing with the existing antennas. In terms of new products, we are coming out with a series of antennas that I would liken to Lego blocks. They?re antennas that are designed to be mounted in hidden places. Places like behind, say, an advertising sign in an airport or some public space. You can configure them by combining them. If an operator needs more gain, or more directionality, a combination of two, or three, or four of them can be easily be placed together, or back to back. Lots of good applications, so we?re really having fun with the small cells. Monica: Operators require a lot of flexibility. They?ve got more bands, but also they have more services to support. One class of services that is going to create a wide range of demand requirements and new traffic loads is IoT. There you have different types of services, different type of devices and use cases driving your opportunities. How is IoT going to impact what you do, and how can you help operators get into that market? Jim: Good question. Boy, IoT is coming fast. It?s coming faster than we maybe thought it was going to. Things like the connected car, for example. We are starting to build the 5.9 GHz, for example, into antennas so we can participate in that connected car business when it occurs. Kathrein is a huge supplier of automotive antennas as well, so it?s a natural tie in. As the supplier to most of the major manufacturers in the world we?re already thinking about how we?re going to support connected car, leveraging those antennas. Of course, with the IoT, there are many layers. Kathrein also has a broadcast solution ? in fact we have been providing these since the 1950?s. When you have slow data applications, we may tie them into broadcast facilities. We have satellite solutions and hybrid fiber coax. All of these tie together to create a connected solution. We?re trying to coordinate our efforts in all of those things for IoT. Monica: How do you see broadcast fitting into the IoT expanded usage, congestion, small cells? Jim: Great question. Broadcast spectrum will be auctioned via the FCC repack. Remaining broadcasters after the auction are evaluating the ATSC 3.0 standard that will allow 2-way communication in their spectrum. If implemented and adopted, this will provide an enormous amount of bandwidth for IOT applications and backhaul for wireless carriers. Broadcasters will more than likely follow what the wireless carriers are already doing ? densifying their networks with small cells. Monica: Broadcast, it?s a concept we have been working on for a long time, in terms of how we actually do it. There is a lot of potential, but what?s the best way to harness it? With the increase in demand, we?ll have to see how that plays out. Jim: It also could be things like what they call LoRA, which is the 900 MHz. We?re also seeing L band, the 1500 MHz. All of those frequency blocks start REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |63| tying into the internet of things. You start using them in the most appropriate way for whatever layer you?re trying to accommodate. Monica: IoT would require additional bands. Do you think there are going to be separate bands reserved to IoT, and specific applications with IoT ? say, connected cars, or something else? Jim: They all have appropriate usages. From meter reading to applications with low-latency requirements, you?re going to utilize more than one technology. Where you?re reading a meter once a month, you don?t care when it comes in. When you?re trying to maybe do an emergency broadcast, you might have a different technology. They all are going to be useful tools down the road. Monica: The availability of new bands enables operators to have small cells and micro cells working on different channels. This would simplify life for everybody involved, because you do not need to coordinate small and macro cells. At the same time, we still have a lot of co-channel deployments, where macro and small cells are using the same spectrum, and interference has to be managed. That has been, for a long time, a major concern for operators. How can we address that? Jim: It is a tough question. The more frequencies you put into usage, the more multiband antennas we have, the more combinations for intermodulation that you have. That?s one aspect. Then again, you?re trying to deal with not interfering with the macro level. Really, placement is key. Adjustable beams are key. Probably adjustable power on radios is key. You can optimize a network that way to minimize those overlaps. Every situation is going to be custom tuned, so to speak, as you try to optimize the network. Monica: You mentioned at the beginning that you have been focusing personally on the US, and listening to what you hear from your customers. You?re also working for a company that?s based in Europe. Can you tell us a little about what it is you hear that?s different in these geographies? Jim: In different places in the world, really, the main difference is spectrum availability. That?s one obvious area. There are different regulations in different countries. In Europe, for example, the height of an antenna is much more tightly controlled. In Europe, they also will tend to limit what they call the lower-side lobe. They?re more concerned than we are in the US about RF exposure to people. They tend to have really stringent standards for that. In fact, that was an interesting part of the Street Connect Solutions. Switzerland has one, if not the most, stringent requirements for RF exposure in the world, by about 10 times. That was actually a great proving ground for the product in terms of that RF exposure issue, which we really had to deal with. We?ve done a lot of testing here in the US and have active trials going on. We?re very conservative in our RF exposure, the maximum permissible exposure. Yet we?re trying to make the system work well. We?re trying to get as much input power as we can, because we want to get good coverage and good performance out of it. Those are all the things that we?ve been doing in our trials. We?re really figuring out how to prevent RF exposure, or interference with the macro antennas. We?re ready to move forward, actually. We?re at a point now where we?ve made good progress there. We?re ready to actually start installing these. Monica: That?s exciting. One other thing is that with small cells, it seems like the technology is there ? we?re all ready to go. All the vendors are REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |64| ready. Most of the time, the big challenge to rollout is really the operational part ? installing it, getting all the permissions right away, electricity, power. How do you help, and how do you see that helping in terms of reducing the complexity, and getting a business model that works much more smoothly than it does today? Jim: Good question. One way is to partner with other vendors, vendors that might focus and specialize, say, on advertising signs, who may already have rights-of-way in cities, who maybe have already worked with city governments to establish agreements where they have expedited zoning permits and approvals, and in many cases, where they already have power and fiber in the ground. Another is education at the government and local levels -- providing the necessary information to ease the process. And another is for us to continually innovate with new antenna solutions and concealment ideas. You?re absolutely correct, it is a time-consuming process to figure out ways to get the right-of-way, the permissions, the zoning, and so on. Again, it seems like many of the larger cities that need this coverage are being very cooperative with us. We actually have that in our favor. Monica: Let me ask you, as a final question, about what it is that you at Kathrein are working on in order to get ready to meet the challenge over the next years. Jim: It really comes back to evolving the quality solutions that we have ?adding new bands to them for operators who really want to future- proof their systems. Adding the 3.5 GHz and 5.8 GHz, that?s a big deal. Adding the 4x4 MIMO capability, particularly at the high-band frequencies, is a big deal. Everybody wants it. They all want to be ready for it when it comes. Then adding these flexible products that allow, in many cases, to install an antenna in a nonconventional location. Those are really the directions that we?re headed with the small cells. And of course laying the groundwork and providing the latest research and development into 5G technologies -- especially millimeter wave. Monica: This is all new. With small cells, we have the need to have telecom infrastructure everywhere. But you want it to be less intrusive and, where possible, hide it. Jim: Right. Interestingly enough, we?ve done simulations ? say, for example, in Manhattan ? where we?ve taken a series of conditions and parameters that we plug into design software. We compare the performance of different models. It could be external antennas on light poles, versus Street Connect, versus a canister. We look at the different heights of installations: how high. We have found that that?s a critical element. How high do you put that antenna? We can make evaluations, then, on which are the most effect tools for a given situation. It?s also interesting, really, that the performance doesn?t vary that much between the Street Connect and what we call a slim-pole antenna, which is a small antenna, or the barber-pole antenna. Actually, it?s encouraging how well they all work in their right place. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |65| About Kathrein Kathrein is an innovation and technology leader in today's connected world. Kathrein solutions enable people to globally communicate, access information, and use media, at home or on the road. From mobile communications, signal processing systems and optimized data transmission in buildings; to fiber optic and cable networks and satellite reception technology; to radio and TV transmission and data reception in cars; Kathrein is a hidden champion and family-owned enterprise that has been working on the technologies of tomorrow since 1919. For more information, visit: About Jim DeKekkoek Jim DeKoekkoek took the role of Product Line Manager in April 2015 with responsibility for Base Station Antennas and Small Cells for Kathrein in North America. Mr. DeKoekkoek started his career in RF with the U.S. Air Force as a SSB Ground Radio Tech and also worked in an Electrical Installation Squadron installing aircraft control tower radios. After 6 years in the USAF, Jim held positions at General Electric Mobile Radio, Zetron Inc., and Kathrein-Scala Division. In total, Jim has more than 40 years of experience solving wireless communications problems and has a BA in Accounting from Dordt College in Sioux Center IA. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |66| Profile Rohde & Schwarz Headquartered in Germany, Rohde & Schwarz has been a main player in wireless communications testing, measurement and monitoring for over 80 years. In addition to mobile wireless service providers, it serves multiple markets, including fixed wireless, broadcasting, electronics, automotive, aerospace, government, security, and public safety. Its solutions encompass five product areas: test and measurement, broadcast and media, cybersecurity, secure communications, radiomonitoring and radiolocation. In mobile wireless, Rohde & Schwarz provides a wide range of products that span mobile phones or UEs, and mobile-network testing. In terms of access technologies and services, the company supports all 2G and 3G legacy technologies, LTE and 5G, in addition to Wi-Fi and short-range technologies such as Bluetooth. Within LTE, Rohde & Schwarz covers VoLTE and voice testing, CA, SON, Wi-Fi offload, and public safety ? both for FDD and TDD. An emerging area of focus is IoT, where Rohde & Schwarz provides measurement and testing solutions for eMTC/LTE-M and NB-IoT. In preparation for 5G, Rohde & Schwarz is working on products for wideband, millimeter-wave, and new waveforms yet to be adopted, as well as advanced technologies, such as massive MIMO and beamforming. Products that help mobile operators and network equipment vendors test and optimize network elements that are affected by densification include these: ? Freerider III, a portable/backpack benchmarking solution for indoor and outdoor testing. ? TSMW Universal Radio Network Analyzer and TSME Ultracompact Drive Test Scanner, two test-drive scanners used to tune, install, optimize, monitor and benchmark models. The TSMW Universal Radio Network Analyzer is designed to support MIMO and CA. TSME Ultracompact Drive Test Scanner is compact and hence also well suited for indoor environments. ? ROMES4 Drive Test Software for network analysis and optimization that works across wireless interfaces. ? CMW500, a platform for testing the wireless interface of mobile devices. It can be used across technologies and architectures, and in conjunction with SON. ? SMW200 Vector Signal Generator, with up to 2 GHz of internal modulation bandwidth, used to generate high-quality, digitally modulated signals. ? FSW Signal and Spectrum Analyzer, and RTO Digital Oscilloscope, with up to 2 Gbps bandwidth, for RF testing in TDD and FDD environments. ? TS8980 RF Test System Family, for RF conformance and operators? acceptance tests. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |67| Rohde & Schwarz Testing a densified network A conversation with Jeremy Cline, North America Product Manager, and Rob Wattenburg, North America SwissQual Business Director Monica Paolini: Our conversation on densification at Rohde & Schwarz is with Jeremy Cline, the North America product manager, and with Rob Wattenburg, North America SwissQual Business Director. Jeremy, can you tell us what Rohde & Schwarz is doing in the field of densification, and what you and Rob are doing specifically in this area? Jeremy: Rohde & Schwartz is multifaceted. We?re, generally speaking, an RF test-equipment manufacturer. Rob and I work on the field side. We?re constantly working on providing our customers the ability to perform outdoor drive tests, as well as indoor walking tests, mainly to verify network coverage and quality provided by the ever-increasing number of small cells and all the other strategies you hear of as part of network densification. I?m the North American Product Manager for Mobile Network Test. That?s a market segment for which we have a dedicated product portfolio to address the challenges that network operators and customers, alike, face due to these new network densification strategies. My colleague, Rob Wattenberg, is our North American Business Director for SwissQual Products. He talks with our R&D department in Switzerland on a consistent basis, to make sure all of our strategic decisions are made according to what we see in the market, and to ensure that we have a coherent product offering. Monica: There have been changes in the way we test network performance, driven by operators? need to capture QoE. With densification, how is testing going to be affected by moving the focus towards QoE? Jeremy: There absolutely is a shift towards testing QoE. That?s one of our top priorities. We?ve known for a while that KPIs only tell a part of the story. When?s the last time you went to a ball game at a stadium venue, for example, and you were worried about ?What?s my RSRP look like?? Maybe some of us RF engineers do, but the layperson is more worried about subjective things like audio quality and video quality. They want to know ?Is my YouTube video that I want to download coming through? And if it does, is it coming through in an acceptable manner, where there?s not a lot of blurring and things like that?? There?re so many aspects of what we call the real- world customer experience that it?s become truly key to test and verify the power of a mobile network. Something I?ve noticed over time is that our typical use case for our products has evolved to a more hands-on, walking-around type of testing, whereas before it was traditionally you walk out to your car, slap an antenna on, put the scanner in your front seat, and go do some outdoor drive testing. There?s still a little bit of that, but really things are moving indoors. As densification methods like small cells and LTE unlicensed bands start to get used, and you?ve got Wi-Fi offload going on, the focus on QoE is just going to become more and more important, to reflect what customers are actually seeing and feeling. Again, I?d say it?s more about the actual data throughputs that can be achieved and other subjective measures that everyone can relate to. Monica: When it comes to utilization, you mentioned indoor access. We know that most of the subscribers and most of the traffic comes from indoor locations. As you say, you still need to go around with a car, but you also need to go inside the buildings or try to capture the indoor performance. How do you do that? How will you need to change the way you work or how your solutions work, to capture that? Jeremy: One of the trends we?re seeing is that small cells are really moving indoors. Generally speaking, we?re familiar with the inner workings of the macro network; that?s a fairly mature technology and infrastructure. But as small cells move indoors, there are going to be quite a few more testing challenges to address. For one, there?re going to be many more small cells to verify coverage for. It?s as simple as that. In a well-coordinated network, you hope that the small cells that are going indoors don?t really have REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |68| any effect on what?s going on outdoors or vice versa. If the small-cell network is well designed, you?re probably not going to create those kinds of problems on the macro side. But the new challenge we?re seeing is in the third dimension, meaning altitude. When you want to get access to the signal, you walk or drive around, and typically it?s in two dimensions. For an indoor venue, though, you may have 15 or more floors, so you?re doing the same route but you?re actually moving up in altitude, and now you have to do this 15 different times. It?s more time consuming. There?re more things to take into account. The test tools have to be able to keep up. From a test equipment perspective, we have to worry about providing solutions that are able to verify the coverage for each and every small cell. And the changes we make in our portfolio are driven by all the new devices that get released these days. As things get more complicated in the network, we have to keep the testing process easy. We can?t afford to take a step back in usability. Monica: Many new dimensions are added to traditional testing, where you had only a macro network and phones. Not only do you have different devices, in different locations. You also have small cells sharing spectrum with macro cells. They affect each other. How do you deal with that in terms of testing? Jeremy: You want to have some coordination between the small-cell and the macro-cell networks, even though early on you may not have that. One of the things that comes up is RF interference. That?s something you can never ignore. As if it wasn?t challenging enough before, you?re going to see these LTE unlicensed spectrum bands coming into the picture. Just the sheer number of small cells that are going to be deployed on the network, which could have coverage issues between themselves and/or with the macro cell network outside of a venue. You?ve also got the emergence of self-optimized networks, and the idea is that that will lead to less in-field optimization, but interference is simply something you have absolutely no control of in some cases. But you should never ignore it. You need to be worried about that in the field. If a base station?s receive antenna can detect a signal that shouldn?t be there, that?s really interference, but there?re so many small interferers out there that we know lie in the wrong spectrum. This may not matter with a macro network, because that signal, with its path loss and its geographic location, may not be picked up by the base station, meaning it?s not really a threat. But now when you start to look at small cells, there?re going to be so many more deployed in the network. They could be closer to these sources that weren?t really a threat before but now they are, because a small-cell receive antenna may pick them up. In some ways, you could argue that they?re more susceptible to interference. That?s just going to add another layer of complexity. It?s going to be important to have interference tools just like we do today and did in the past. In the future it?s going to be even more important to locate these signals quickly and easily and efficiently and get those issues resolved as fast as possible. Monica: With small cells, it?s more than just having smaller-footprint equipment. A lot of things change. As you say, sources of interference might change, but also the way we deploy them and test the small cells. You might have less-skilled technicians installing them and testing them. The location is different, and the networks will change. The dynamics of the network change more quickly. The operator might continually add small cells at a faster pace than they do with micro cells. How is that going to change the way you test the network? More dynamic network, less-skilled employees? Jeremy: That?s certainly a concern. As we go on from 2G, 3G, 4G, and now we?re looking at things like 5G and IoT, the network is getting more and more complicated. You?ve got all these strategies REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |69| related to network densification, like small cells, heterogeneous networks, and LTE and Wi-Fi coexistence. Testing equipment is expected to keep up. We have to put in all these bells and whistles, you have to be able to verify performance, but the test equipment cannot get any harder to use. Speaking from my own personal experience visiting with our customers, I?ve noticed a trend toward the idea that they?re going to change who does what in the company, and the person holding the test equipment may not have much RF background or experience. They still need to be able to use the tool. Ease of use is definitely at the top of the list from a testing equipment perspective. That?s something we?re focusing on, and it?s going to be absolutely critical to have, especially if the network gets more complex. The other thing I?ll add is that we see a need for automation and remote monitoring, as well. You look at, again, this number of small cells that are going to be deployed in the network. They already are, and it?s just going to grow exponentially through 2020 and beyond. Expecting a cell technician, for example, to go out in the field and verify all of their sites in one day is almost becoming unrealistic. There?re just too many sites that they?re going to have to be worried about. Instead, we may see some testing requirements where you leave a scanner or a UE at a site, and you can log into it anytime, 24/7, to see what?s going on. Advances in the Android operating system have really changed the way these tools are interacted with. We get access to the chipsets. We get from the devices all these KPIs that we need in order to look at some of the things I?ve already mentioned, like data throughput, and voice quality, and video quality. We get a whole lot more information than we used to. Again, it all comes back to the ease of use and allowing anybody to pick it up, turn it on, and press go, and get what they need. Monica: Ease-of-use and automation are crucial for dealing with increased complexity. One source of complexity that you mentioned earlier is that operators? use of unlicensed bands for Wi-Fi, LTE unlicensed, or other access technologies. How do you deal with that? To test for performance in an unlicensed band, it?s inherently more complex. Rob: From our test tool point of view, there are a couple things we have to be concerned with. One is obviously the RF environment. We have tools to be able to properly assess that RF environment. We?ve got a good line of RF scanners that are software defined. We can evolve with technology. We can evolve with spectrum band deployment ? which is probably even more important than the RF environment, which, as Jeremy referred to earlier, is pretty robust. Once you?ve got these things installed, they tend to function in the RF domain. The next thing we really have to be focused on is the functionality. If I?ve got a device that?s made to be able to use LTE unlicensed or maybe in aggregation between LTE and Wi-Fi, how does that device manage the flow of information through the IP domain? That?s where a ton of our energy is going these days. We?ve got a company called ipoque that is a Rohde & Schwarz company, and we have taken their deep-packet inspection capability and REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |70| integrated it into our tools so we can watch the IP flow. Most of the problems we?re seeing today are not caused by RF deficiencies, but through packet routing. Maybe some networks are filtering packets that shouldn?t be filtered. Maybe they?re not being prioritized properly. Maybe there?s packet loss. These are the things that we have to help engineers figure out how to solve. We take what is essentially the end-user tool or device, and it?s really important for us to use that particular thing. We can?t use a generic device to test these complex networks. The phone that you and I go get from a carrier is what we have to use. I can go get a phone from Europe, bring it over, unlock it, and use it on some of these networks here in the States, and it doesn?t perform the same way. It might not work properly. For instance, if VoLTE doesn?t work, we have to use the carrier?s end-user device. We buy that, we have to integrate our software into that, and then we have to layer on top of it functions that are essentially mimicking what you and I would do with our phones. It might be, ?Hey, I?m going to go surf websites.? I might go look at videos. I might do a VoLTE call. I might do a video chat. These are all things that we have to do to drive the devices to test these networks. The complexity in this densification is the aggregation of technology bands. The functionality of each has to work in concert with all the others. Troubleshooting the problems that arise from that is really critical. Just to take a quick step back, when we program these phones to do what our end users do, we have to be able to measure what they experience. That?s where quality of experience really becomes critical. I don?t care if I get a gigabit per second out of my mobile phone. All I care about is can I have a video chat with my kids who are away at college? Those are the things that are more critical to me. I can give you hundreds of examples of real-world issues we?ve had, where we?ll go do an Ookla speed test and see 30, 40 mbps on a mobile phone, yet I can?t download a 500 MB file in less than four hours. There?s a problem somewhere out there in the network. We?ve got to be able to provide the background information that engineers need to understand where these problems are coming from. Monica: That is a challenge, because different applications have different requirements or generate different types of traffic. If you test the overall performance of the network, you might not be able to see the difference there. Rob: Exactly. I would say this in terms of latency. Video is really one of those hot-button items. We?ve seen a number of studies that show that video is going to be 75% of all bytes that flow in the network by 2020. Looking at video and latency, those things can go hand in hand, but in some cases, it?s not quite so important If I?m looking at a YouTube video, latency is not so critical. If it?s a video on demand, let?s say the typical use case, I would go to YouTube and watch a video that somebody uploaded at some time in the past; that?s really nothing more than a file download in disguise. In this case we?re talking about YouTube. It could be Hulu, Netflix, Pandora. There?s all kinds of delivery mechanisms out there for voice and video. They all have strategies in terms of how the bytes flow. Their emphasis is on delivering the best quality of experience to the guy who?s using the phone. Latency?s not so important there. I don?t care if there?s a 10-second delay in the flow of packets. That?s not a critical element there. When we move into, say, live video, where I?m watching the Olympics on my phone, now latency can come into play. Again, do I really care if that video is coming to me three seconds delayed or five seconds delayed? The typical delay we see in watching on a mobile phone on a live video is 5 to 10 seconds. It does matter in terms of the throughputs. If I?m looking at a video on demand, I can get a buffer filled in a high bandwidth network very quickly. You get a spike of data coming to your phone. It plays out. As the buffer empties, another spike of data rolls through, the buffer gets filled back up again, and everything plays out smoothly, and I?m a happy customer. For live video, you don?t have the luxury of buffering 40 seconds of video. You get much smaller chunks of data, which means you?re now much more susceptible to dropouts and data throughputs. Latency has an impact there because the higher the latency, the larger the buffer needs to be to overcome problems with it. Lower latency means I can keep my buffer sizes smaller and not worry about retransmission so much, as well. It?s a very complex formula that goes into latency, buffer sizes, how close to real time can we get with the video or audio transmission if we need it in real time. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |71| Monica: VoLTE and conversational video, or ViLTE, are the next challenge. How do you test for performance? Rob: IR.94 ? let?s say an IMS-type video chat ? is very challenging to test in the real world. We see a lot of people who can put things back in the IMS servers and try to assess video quality, but in the end, can you tell if I am a happy customer? The only way to tell if I?m happy is by being where I?m at with the device. When I talk to my kids, for instance, we?ll pull up the phone, we?ll do a video chat call. What happens behind the scenes is everything?s getting routed through the IMS servers. There?s a video socket set up for video packets. There?s another socket set up for audio packets. What we?re doing with our test tool is we?re now running what we call an algorithm. By ?algorithm? we mean that we can run audio into an algorithm, and what?s going to get spit out is a mean opinion score that?s going to grade the quality of that audio from one to five, five being best. I can grade the audio with this algorithm, and I can grade the video with a separate algorithm. Now I?ve got two measurements, or two KPIs, if you will. The third thing that?s critical to understand in a video chat is lip sync. Since audio and video are transmitted on separate paths, you?ve got to be able to come up with a method for calculating lip sync. We?ve seen some studies where they actually put blood pressure monitors on people, and in a poor video environment, blood pressure actually goes up in people. We know that we don?t want to be under any more stress than we already are, so it?s critical for carriers to be able to measure audio quality, video quality, and lip-sync capabilities on these video chat calls. I would say the biggest challenge for us, and we?re very close to releasing this, is that we have to be able to inject video into the device, because we can?t really test reliably with opening up the camera feed and making a video call. We have to feed into the device a known reference clip that?s going to simulate the network properly. A black screen?s not going to transmit any bytes, but motions, face movement, those are all things that actually up the bit rate of the data transmission. We have a video/audio clip that goes out at the same time, and then we put special markers in the video so that we can now calculate timings for the lip sync. Then, on the receive side, we run these algorithms, as well. Those receive algorithms, we?ll be able to go full-duplex audio, video, and quality. On the algorithms, these aren?t simply software pieces that just grade this video. These are algorithms that have gone through incredible amounts of testing. The ITU has issued standards for the proper way to measure video quality in mobile environments. ETSI has recommendations as well. We work very closely with the standardization bodies, and we?re very proud of the fact that we have the approved ITU standard for measuring video quality in a mobile environment. It measures all the way up to 1080p, and we?re in the process of testing it for 4K video, as well. If you?ve got real latency issues, you?re going to end up with real problems of when I talk, you hear it later. We call this mouth-to-ear time, and it is super critical from a quality of experience perspective. Nothing?s more frustrating than what we call double talk, where I talk and you talk at the same time because we?re not quite in sync. There?s an IT standard in terms of when double talk is problematic. Latency plays into that in a big way. That?s a real problem area for carriers. In terms of VoLTE and ViLTE, that?s probably one of the more critical parameters that we?re able to measure. Of course, you still have to look at things like jitter, jitter buffers, the call state that you happen to be in. There?re some specialized tests that we have, just to cover where you?re at with that. We have a special test that we can run to measure the exact amount of latency you have. It?s done through a pretty clever mechanism where we send audio from what we call the A side to the B side. The B side hears it and sends it back, and we can get latency measurements from an end-user perspective based on that. We also have the ability to layer noise in on top of speech so we can see how well the network elements that remove unwanted noise are performing. If we can throw background noise in, say, the conversation we?re having now, hopefully the other end doesn?t hear it. That requires all the right noise cancellation mechanisms to be turned on. Echo is another problem. We?ve got to make sure echo cancelers are working properly. We have specialized tests just to simulate echo. We can introduce echo and measure the ability of the REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |72| echo cancellation components to remove that. Again, it all points back to this quality of experience, measuring audio and video quality. Densification reemphasizes the need to look at this in this manner. We?re in this heavily densified network. Let?s take ourselves forward 10 years. We will have devices that may be hitting the Internet or hitting the IP backbone in several ways in parallel. It is reemphasizing the back-end functionality, and how it might impact the quality of experience. Monica: Absolutely. If we look at the next 10 years, what are the challenges that you are trying to address with IoT or 5G? How are they going to change the way we test networks? Rob: From a tools perspective, we tend to sit back and wait to see where the markets go, where the carriers are actually deploying technology, and then we?re ready to test it. The nice thing about Rohde & Schwarz is we?ve got groups in this company that work with the chipset manufacturers, the device manufacturers, the infrastructure manufacturers, the standardization bodies. We are in the ones and the zeroes of evolving technology. Here on the field side, on the test tool side, we?re leveraging that experience, and we?re getting ourselves prepared for running the kinds of tests that are going to stress these new networks and their functionalities. That?s one of our challenges in looking forward. How will the internet of things matter to us on the testing side? If my doorbell is going to connect to the internet, I don?t think we need a test tool to tell us does that thing work properly, but we do have to understand what its impact on the network is. Network virtualization is coming, and mobile devices might have some clever ways of accessing multiple radio-access technologies, or share RANs. All these have an impact on functionality, so we?ve got to be able to stress that functionality. Those are things we?re working on, as well. The RF environment is going to get more and more complex as 5G comes. Our RF scanning receivers, which have these phenomenal performance capabilities, and software-defined radios, we?re now evolving those to make sure we can really understand the RF environment. One thing, and Jeremy talked about it earlier, is we are looking at how we can better assess interference in this evolving market. Right now, we feel LTE is very susceptible to interference. We?ve seen things like ballasts and fluorescent lights like you see behind me create interference that cuts throughput of an LTE network in half. Finding those kinds of sources of interference is going to be one of those really tricky things for the carriers. It?s spotty. Interference could be up and down, all over the place. Coming up with a mechanism to do that more efficiently is something we?re working on. Back to your point earlier, which is everything has to be simpler than it is today: we have the need for more and more people hanging networks out in the world, the real world, whether it?s in small buildings. I?ve heard some people talk about moving towards 100,000 sq ft buildings and bigger. That?s where we need to be focused. It?s going to go to 50,000 sq ft buildings and then maybe my house. That?s going to require somebody to do some kind of work on site. That guy that does that work is going to have to be extremely efficient. He?s going to have to be able to go deploy, hook up, and test. No longer will we have the days of engineers coming out and doing surveys after the fact. The holy grail for us is a tool that?s absolutely for free. You hit start, stop, pass, fail, and everybody?s happy. Obviously we can?t get to the holy grail, but that?s the direction we?re heading. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |73| About Rohde & Schwarz For more than 80 years, Rohde & Schwarz has stood for quality, precision and innovation in all fields of wireless communications. The electronics group is strategically based on five pillars: test and measurement, broadcast and media, cybersecurity, secure communications, radiomonitoring and radiolocation. The company addresses customers in the mobile radio, wireless, broadcasting, electronics and automotive industries, in aerospace and defense as well as government, security and critical infrastructures. Rohde & Schwarz is among the world market leaders in its established business fields. It is the world?s leading manufacturer of wireless communications and EMC test and measurement equipment, as well as of broadcasting and T&M equipment for digital terrestrial television. About Jeremy Cline Jeremy Cline is a Product Manager at Rohde & Schwarz where he is responsible for products that are primarily used for mobile network testing. During his 6 years with the company, he has specialized in drive test, benchmarking, network optimization, interference hunting, and other general purpose RF applications. Jeremy helps identify testing solutions for RF customers across multiple industries including aerospace and defense, telecommunications, semiconductor, biotechnology and device manufacturing. Jeremy graduated from The University of Texas at Austin with a BSEE, and The University of Southern California with a MSMDDE. He can be reached via e-mail at About Rob Wattenberg Rob Wattenberg is the Business Director for SwissQual products in North America and is based in Irvine, California. Rob joined SwissQual in 2008 as a Regional Manager, and introduced their innovative products and technologies. He brings over 25 years of experience to Rohde and Schwarz in the Mobile Network Test market segment. Rob has held several executive level positions in the wireless industry; primarily related to field testing, optimization, and benchmarking of cellular networks. Rob?s expertise in recent years focuses on Quality of Experience measurement as it applies to voice and video. He holds a Bachelor?s degree in Electrical Engineering from Cal Poly San Luis Obispo. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |74| Profile Samsung Networks Samsung Networks develops network infrastructure products for mobile operators worldwide. Since the 1970s, Samsung has been a leading global mobile infrastructure vendor, and more recently an innovator in TDD-LTE and FDD- LTE technologies. Samsung Networks launched its first commercial FDD-LTE network in the United States in 2010. This was followed by commercial TDD-LTE network launch in 2011 with worldwide deployments from Asia to the United States. A core focus of Samsung?s technology development has been on an end-to-end small-cell portfolio featuring three types of small cells: ? Outdoor small cells, with radio and baseband combined in a compact unit that can be installed on outdoor urban fixtures to increase capacity in dense areas, and to improve coverage where the macro layers cannot reach. According to Samsung, its outdoor small cells can support up to 200 active users in a 20 MHz channel. ? Indoor small cells, suited for installation in public venues and enterprises. These are smaller than outdoor small cells (4 kg) and support 64 active users per cell. ? Residential femto cells, small units (less than 1 kg) designed to be plug-and-play devices that automatically select the appropriate frequency and enforce the operator?s location policy. They support both data and voice (VoLTE) for eight concurrent active users, with up to 225 mbps throughput and a coverage area up to 1,000 sq m according to Samsung. Samsung is also working on LTE Unlicensed small cells, with the first products supporting LTE-U ? the Samsung LTE-U eFemto ? using enhanced Carrier Sensing Adaptive Transmission (eCSAT) for coexistence with Wi-Fi. The LTE-U small cells will be software-upgradable to LAA. Samsung?s small cell gateway, helps operators increase their densification efforts, by aggregating thousands of small cells in to a single connection to the EPC. Samsung?s end-to-end small-cell network enables operators to manage interference among small cells and between macro-cell and small-cell layers. It uses advanced scheduling and cell- coordination technologies that benefit from the tight synchronization that centralized baseband processing allows. Current R&D focus is on 5G: Samsung is working on the new RAN architecture (virtualization, with C-RAN topologies and decentralized core functions moving toward the edge); new bands (mmW bands: 28 GHz, 37 GHz, 39 GHz, and 60 GHz, primarily); improvement of antenna technologies (e.g., MIMO and beamforming); and coexistence with legacy RATs (3G, LTE) that are still widely used. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |75| Samsung Densification from the chipset to small cells A conversation with Nivi Thadasina, Senior Director of 5G and 4G Engineering, Samsung Electronics America Monica Paolini: For this conversation on densification, I have the pleasure of talking with Nivi Thadasina, Senior Director of 4G and 5G Engineering in the Wireless Network Systems division at Samsung Electronics America. Nivi, may I ask you what Samsung is doing to help densification efforts by mobile operators? And what is your personal role within that? Nivi: I?ve been with Samsung Networks for over 10 years and have been involved with small cells since their ideation and inception in 2004, even before the term ?small cells? was introduced. We did the initial research ? partly because of Samsung?s capabilities to undertake development of new technologies and to solve tough problems faced by the operators. We design and offer end-to-end products, as you are aware. Plus, we have the capabilities to design and manufacture our own chipsets. With that in mind we said, ?OK. What is the best way to address a need within the United States?? As part of that, we started to look into these miniature base stations. That eventually led to our world?s-first small cell ? at that time we were calling it ?Internet Radio? ? launched with Sprint. That was back in 2007. At Samsung, my role encompasses responsibility for radio access solutions targeted for the United States. We do the feasibility analysis, propose new ideas and methodologies, new product requirements and the product definition. Once our development team in headquarters realizes the product, it is validated here in the United States before the final delivery to our customers. Our team is also responsible for commercial rollout of small cells for both enterprise and residential markets. Monica: Samsung has been involved in small cells for a long time. I remember in 2007, the Sprint launch. A lot has changed since then, even though we?re still in the beginning of the densification process. Can you tell us how you see the evolution to densified networks? Nivi: In 2007 the need was coverage. In-building was the challenge. The signal was not penetrating where it needed to. The immediate need from our customers was ?Can we get coverage in areas where it?s very hard to reach through macro cells?? Coverage was the initial need. With the introduction of small cells they now had a tool to quickly and efficient address coverage challenges in their network. That eventually led to ?Now that we got the coverage, can we also look at capacity offload?? Especially for users who are on the cell edge of the macro network ? they are the ones who consume the most power and spectral resources, from a macro standpoint. Most in-building consumption could also be classified as cell edge users due to RF signal characteristics. Our customers asked ?OK. Can we also use this product to see whether it could be utilized as a capacity offload tool?? That was all part of the 3G. As part of evolution from 3G to 4G, now the biggest need we see is voice over LTE. ?Can I provide voice coverage in areas that are very hard to reach?? For that, our customers are looking at small cells as ?Hey, can I use this tool to address VoLTE coverage?? With that, obviously, we can provide a better user experience ? better voice quality and significant improvement in call accessibility and retainability. Another added benefit for operators is improvement in spectral efficiency for in-building utilization and cell edge users. We are able to squeeze more bits per hertz while improving overall experience for end users on their cell phones. Looking ahead, as you?re aware, 5G is the next evolutionary step. Millimeter wave can have a very large path loss. Propagation characteristics are tough. I would say that the 5G is a very natural evolution for small cells. Monica: What you were saying with respect to the increased spectral efficiency in 4G is interesting. What you?re seeing is an increase in spectral efficiency in the macro. For instance, indoor small cells not only improve the in-building performance for the people inside the buildings who are closer to the small cell, they can also improve the macro layer. Is that correct? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |76| Small cells help the macro, as well. Usually in the beginning we thought, ?You just put a small cell for the people using the small cell.? It may benefit even more the people who are at the edge of the macro. Nivi: Absolutely. I hear many encouraging comments from the operators about average sector throughput increasing after addressing those tough users deep inside a building or on the cell edge. That?s mostly due to the fact that you are able to close the link between the UE and base station with improved MCS rates, higher bits per hertz and less power thus resulting in lowered interference levels. Definitely, I think it?s a win and win for both the macro-cell and small-cell layers. Monica: Do you see a shift between indoor and outdoor locations in the operators? densification efforts? Nivi: Samsung has been focused in indoor for a couple of different reasons. There are already widely published statistics showing that 50% to 70% of the calls originate from deep inside the building. There are also estimates on how much of the indoor spectrum is under-utilized by the operators. These numbers vary; however, the primary concern is the disparity in coverage between the outdoor and indoor environments. Spectrum, among others, is clearly the most valued asset owned by an operator and that is under-utilized in indoor environments. By deploying a small cell deep inside a building, they are now able to light up the high valued resource. From Samsung?s standpoint, we see this as a great opportunity, as we?re able to help our customers to address and relieve the macro network by reducing capacity demands from users deep inside a building. Plus, you are able to go address the voice over LTE challenges that operators face, which are typically in indoor locations. Monica: Couldn?t the operators use Wi-Fi Calling instead? Nivi: Very good question. There are different opinions on that. Let?s say you make a voice call over Wi-Fi and that the call experiences voice quality challenges. Or, worst, the call drops. Transitioning or handover between Wi-Fi and macro networks is not seamless, and may result in poor voice quality or frequent drops. In that case what would an end-user do? The user will naturally call the operator to complain since most end-users can?t decipher whether the root of the problem is with their home Wi-Fi coverage or the operator?s macro network. The operator is unable to trace user experience since that particular call is handled by a network that is outside of their domain, i.e., unmanaged network. One way to address it would be by moving that call from Wi-Fi to voice over LTE, all of a sudden I am now able to go see and predict the user experience. That?s one thing. The second is that it?s well publicized that with Wi-Fi, the coverage within your home is still somewhat restricted compared to coverage you can experience with the small cells. Based on our product experience, we have received positive feedback from the field on how noticeable was the coverage expansion in their homes relative to Wi-Fi coverage. Now they are able to make calls in areas where they could not before. Monica: 5G is a huge opportunity, because wireless networks will be able to use a wider range of spectrum bands. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |77| At Samsung, how do you see those new bands? Some of them are traditionally not cellular bands, like millimeter wave. How do you see them being used for densification purposes? Nivi: You saw the FCC ruling that came out recently. They?re immediately looking at four bands. That?s great news for all of us. The 28 GHz, 37 GHz, 39 GHz, and 60 GHz. Right now we?re doing a lot of work in 5G in this area. We?ve been looking at 5G for the past several years. From our standpoint, we see a great opportunity. There is an immediate opportunity in 28 GHz. Overall we are looking at multiple different solutions for 5G to provide blanket coverage in both outdoor and indoor environments. By virtue of Samsung?s strong presence in small cells, we strongly believe that we have a distinct advantage as we have deployed the most field proven solutions in this space. Monica: What kind of bands are you seeing that are better suited for indoors versus outdoors? Is it backhaul or access? What?s the best way to leverage it? Nivi: Our customers will deploy all the way from sub-1 GHz, namely 600 MHz, to millimeter wave. It?s already well known that once you reach millimeter wave, the in-building penetration can be a challenge. We have product solutions that allow our customers to solve such problems. Our customers use various high and low bands to selectively address various use cases and coverage needs inside and outside buildings for access. Monica: There are two different views you can take. As we move higher in frequency, the range is shorter. That can be an advantage in an indoor location because it?ll have less interference. At the same time, you need more equipment because the range is smaller. If you have a cell with a range so short that you need a high number of them, is it cost effective for an operator? Nivi: We are looking into various technologies to extend the range of 5G in millimeter waves well beyond what the industry initially envisioned. Does this mean a millimeter wave based 5G cell will equal sub-2 GHz cellular levels? Not yet. Combination of massive MIMO and adaptive beam formation, as an example, will significantly improve the link budget by virtue of generating narrow beams and large improvements in transmission gain. I think some of these technologies and techniques are utilized to overcome the path loss. We do believe 5G is ready for commercialization. We have done extensive demonstrations and trials to validate how to close a 5G link at much greater distance to allow cellular like deployments. I do believe that the 5G deployment pattern will be combination of macro cellular and small cell footprint. It will utilize various configurations from street furniture, rooftops, and existing cell towers to fulfill coverage and capacity demands. Monica: There are going to be many solutions out there. That brings up the issue that not only do you have different solutions, different locations, but also different vendors. How do you view that? This has been a challenge for a lot of operators. They want to have equipment from different vendors, but integration is not easy. What?s your view on this? Nivi: When we first approached small cells, we encountered similar challenges, with not only 3G but also 4G networks. Typically, most operator networks for macro deployments are homogenous within a given market. A single vendor covers the entire network. If you are not an incumbent vendor, this can introduce additional challenges. Knowing that we are not an incumbent player in all the US markets, we designed our products from day one to underlay a macro network. Intrinsic to the base layer of our HW and SW is ability to co- exist within any incumbent markets. Now the question is ?How can we coexist?? Not only can I coexist, the end user should not know the difference that ?Hey, I?m on a Samsung network or someone else?s network.? The handset should seamlessly move between these multi- vendor solutions. There are certain innovative ideas we had to incorporate into our products to seamlessly coexist. On top of that the coexistence will come in two forms. One is ?How can you coexist?? from a radio standpoint, and the other is ?How can you coexist?? from a core network standpoint. There are different solutions to address the radio and the core network. In my opinion, 3GPP has done a very good job in terms of coming up with well-defined interface specifications, which make it bit easier for multiple vendors to interop. However, there are certain things operators can still do, especially in the X2 area, to further promote multi-vendor co- existence. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |78| SON is another area in which interoperability is crucial. It?s not necessary to have a vendor- agnostic SON. But, certainly, having that would help promote a truly multi-vendor radio network. Monica: There are also different technologies. We have LTE, but operators are also using Wi-Fi as a complementary radio access channel. Then we have LTE unlicensed ? either LTE-U or LAA, LWA, MulteFire. This opens the way to another level of tight integration of performance across different access channels. What are you doing there? How do you see this further developing? Nivi: You?re right. The technology is getting more and more complicated. Not only are you looking at multiple bands, multiple technologies. Now you?re looking at a combination of LTE and Wi-Fi and so on. There might be three or four different flavors of this technology. You might see a combination of LTE and Wi-Fi, since Wi-Fi is prevalent. You might see LWA solutions out there. LTE-U is something that we are aggressively pursuing. Certainly you?ll see that plus LAA. Of course, MulteFire is also out there. Each of these solutions has its own pros and cons. Eventually this industry will evolve and hopefully will converge. Monica: What are you working on with Samsung today in preparation for the next five years? What is the focus for the future with respect to densification? Nivi: We are certainly working on lot of exciting things, in terms of how we can capitalize on our experience and lessons learned from 2G, 3G, and 4G into 5G. Plus, as an industry, I think there is a rapid evolution from physical elements to virtualization. Samsung is clearly looking at all the different opportunities, technology evolutions, talking to different customers, not only in the US but worldwide, in how best to design our solutions to fit their needs. One of the biggest strengths Samsung has is that not only can we provide complete end-to-end solutions, but also build our own chipsets. That plays a strong role and hopefully influences the evolutionary path for our customers. Monica: You have your own chipsets. You mentioned virtualization. Does it mean also that you?re working on the C-RAN part of the solution for small cells? Nivi: We have launched C-RAN in Korea. I think that?s already well publicized. When I mentioned virtualization, the approach to virtualization for core and RAN will differ. Unlike REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |79| for core networks, I do believe that RAN virtualization will probably encompass combination of physical and virtual elements with various functional-layer splits. A small cell is essentially either a complete eNodeB in one box with, say, an Ethernet backhaul or low power RRH each to scale to meet market goals. As we evolve towards 5G, what makes sense is a combination from having all the layers stacked in one box, to a combination of having a radio plus everything else perhaps virtualized. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |80| About Samsung Headquartered in Ridgefield Park, N.J., Samsung Electronics America, Inc. (SEA), is a recognized innovative leader in consumer electronics, mobile devices and enterprise solutions. A wholly owned subsidiary of Samsung Electronics Co., Ltd., SEA is pushing beyond the limits of today?s technology and providing consumers and organizations with a portfolio of groundbreaking products in mobility, virtual reality, wireless infrastructure, wearables, electronics, and home appliances. Samsung is a pioneering leader in smartphones and HDTVs in the U.S. and one of America?s fastest growing home appliance brands. To discover more about Samsung, please visit For the latest Samsung news, please visit and follow us @SamsungNewsUS. About Nivi Thadasina Nivi Thadasina is Senior Director of 5G and 4G Engineering at Samsung Electronics America, where he is responsible for radio access network products in the U.S. Previously, Nivi led engineering efforts for the first commercial launch of LTE service in the US market with MetroPCS that utilized Samsung?s evolved NodeB and evolved core packet products. Nivi also led the development of the world?s first commercialized femtocell and holds several patents for radio frequency technologies optimized for indoor environments. Prior to Samsung, Nivi worked in engineering roles at Bell Northern Research and STMicroelectronics, where he was involved in the design of 2G and 3G Wireless communications systems and Very-large-scale integration (VLSI) chipset development. Nivi holds a Bachelor of Science in Electrical Engineering from University of North Carolina, Charlotte, and a Master?s Degree in Electrical Engineering from the University of Texas, Dallas. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |81| Profile SOLiD Over the years, SOLiD has developed RF amplifiers, RF radios, and optical transport solutions designed to enable cost-effective densification of mobile networks, increasing capacity and coverage through DAS and small-cell deployments. SOLiD offers both outdoor and indoor DAS installations that target a wide range of locations, from large venues with high capacity-density requirements, to slightly smaller commercial venues ? which SOLiD calls the Middleprise. In the past, Middleprise venues have been challenging for DAS deployments because of the complexity and cost of traditional DAS. SOLiD?s goal is to change this and make DAS attractive to smaller venues as well as to large ones. SOLiD DAS solutions support multiple verticals, including entertainment (e.g., stadiums, arenas), mass transit, healthcare, education, retail, hospitality and enterprise. The ALLIANCE Multi-Carrier DAS platform is SOLiD?s flagship DAS solution. It supports neutral- host deployment models, and works in frequencies ranging from 150 MHz to 3 GHz. Remote units are available at different power levels, each suited to a different venue and topology. Lower-power ROUs are well suited for smaller venues and public safety networks. Higher- power ROUs are most commonly deployed outdoors or in venues with high traffic loads. The ALLIANCE platform also includes: ? The ALLIANCE BIU and eBIU, the head-end that filters traffic to the base stations. ? The ALLIANCE DMS, used to manage the DAS. ? The ALLIANCE OEU, an optical multiplexing device to expand coverage to additional buildings. SOLiD also offers the EXPRESS Single-Carrier DAS, a multi-band solution developed for indoor and outdoor environments where only one operator has a presence. The EXPRESS Public- Safety DAS is a variation of the Single- Carrier solution, designed for the public-safety market. In the optical backhaul and fronthaul area, SOLiD has been a leading proponent of DWDM, which splits a single fiber strand into multiple bidirectional channels to increase the capacity of the fiber, multiplying the capacity of the link. Linear add/drops enable the operator to use the same strand to serve multiple small cells, and to provide both fronthaul and backhaul. The DWDM solution, Infinity Access, supports multiple protocols (e.g., CPRI, OBSAI and Ethernet) and can simultaneously support multiple access technologies (e.g., LTE and Wi-Fi) in the same strand. Operators no longer need to add a new fiber link when they add a new RRH or a small cell. Moreover, because DWDM allows operators to gradually add new links to the same strand, they can reduce their deployment and operating costs as they expand their networks. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |82| SOLiD Densification in the Middleprise A conversation with Ken Sandfeld, Executive President of SOLiD America Monica Paolini: Today I have the pleasure of talking with Ken Sandfeld, Executive President of SOLiD America. Ken, let?s start by talking about what SOLiD is doing in the area of densification, and what you?re personally involved with. Ken: At SOLiD, we?re focused on in-building wireless coverage with innovative indoor DAS solutions and bringing new in-building technologies to the enterprise ? and now specifically to the Middleprise segment of the business, to be able to broaden that market space. Middleprise densification is a priority right now. The other area that we spend a lot of time in is new solutions for outdoor environments ? in particular for dense urban environments. We believe we can do that differently than some of the solutions that are currently available. Monica: How is the balance between indoor and outdoor infrastructure changing or evolving with time? Ken: There?s no doubt we?re more focused on in- building than on outdoor, mostly because we see there?s a huge demand coming from the in- building space. We all know that. In terms of the time spent, that?s also where more of the problems are, so to solve those problems would be very striking. Most of what?s going on in the outdoor space right now is small cells ? deploying more and different types of small cells and solving for that environment. So we?re also working on what would be essentially outdoor DAS solutions to compete with small cells, or augment and work with small cells. There are some significant oDAS solution advantages over small cells: oDAS can be smaller, and deliver more service and more spectrum than a small-cell solution can. It just hasn?t evolved to that point yet, but we think it really can. We?ll have to see how that goes. Monica: How about the cost? Ken: The cost is actually lower, because you?re putting less electronics on the pole. The largest part of the electronics is kept back at the C-RAN location. From a future-proof perspective, you are actually not pushing protocol-dependent electronics out to the pole, and that fact has always made DAS so attractive from an outdoor perspective. It doesn?t mean you?re giving up a lot of functionality. You still have all the controls at the C-RAN to be able to do SON and interference management. You?ll just be doing that at a different location. Monica: If you have indoor infrastructure, you are more shielded in terms of interference, but that is still something you have to consider. You either deploy on a different channel, or you have to deal with interference. Ken: Until we have all those additional bands to play with and the use of unlicensed bands with LTE-U, there is a need for systems and software that are getting smarter. However, there may be a period where the in- building handoff to the outdoor, and vice versa, will not happen. I do believe there is just going to be a gap in the data as you go from inside to outside, maybe only a second long, but there will be some issues. Over time it will get better, when you have stronger virtualization of software-defined networks. You?ll essentially have APIs that will allow an ecosystem of people to all play on the same playing field when it comes to SON, and being able to optimize third-party solutions. Once that happens and solutions are more standardized, then we?ll see a lot more cohesiveness in those hand-offs. Monica: We had this great promise of having massive densification on day one, of small cells everywhere, but it?s actually taking longer. Why do you think that is? Ken: From an in-building perspective, the challenge with the solutions currently on the market is that either you have a solution that has more active electronics, where you?re putting radios on the ceiling, essentially a more traditional approach, where you?re putting a small cell on the front end of a DAS. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |83| Alternatively, you may simply deploy a small cell in a closet and then just radiate the signal from the closet. To date there hasn?t been a hybrid solution that brings it all together. You have the smaller buildings where you can put two, three, or four eFEMTOs, small cells, and you just put them in the building and you cover that smaller building. As you get to larger spaces, your options increase. Either you distribute RF or you can distribute radios around. There?re some solutions that do both. The problem with distributing radios is, how do you scale with multiple operators, more bands? How do you deal with the additional cabling? And deal with the costs associated with adding more to it? Your TCO goes up. Or you can distribute RF. Monica: There are different solutions out there. Is it the technology or the cost that has been slowing down deployments? Ken: There are two parts to that. There is the actual infrastructure of distributing or radiating the RF, delivering the RF to the user. I think those solutions need to be Wi-Fi like, low- cost devices that can support multiple operators. Ideally, you want solutions that can scale to multiple protocols and multiple bands without having to add more electronics on the ceiling. Then you have the connection to the core, which is probably the bigger cost driver, because that gets into the business model issue. If the enterprise can?t connect to the service, including the operator connection portion, then it doesn?t matter how good the RF solution is, it?s useless. You ultimately need one simplified solution that will bring those two things together. Frankly, it?s what the network operators require; also, carriers can?t support an environment where they have to roll trucks and engineers to turn up a small project. It needs to be a self-installed solution, and potentially self-optimizing or self- conditioning too. Monica: How does the business model for small cells work in practice? How does it relate to the DAS neutral-host model? Ken: SOLiD believes that DAS and small cells will become a hybrid, yet simplified, solution and will be deployed by third-party owners and/or neutral hosts, as they often work directly with building owners that don?t want to own, manage or deal with these systems. This will change the business model for the operators. Operators don?t want to devote a lot of resources. They just want to manage their service and their KPIs to guarantee that their licensed signal is not being interfered with. Ultimately, all the parties need a win-win solution. In order to do that, you need to bring the whole thing together in one simplified architecture. The days of having multiple, disparate systems ? it?s just not affordable or attractive for anyone to deploy that. Monica: When sharing infrastructure, operators may worry that they will lose control and exclusivity. How do you think they?re dealing with that? Ken: They don?t need to lose control or exclusivity at all. In the model that we see developing, the technology allows every operator to have its bands, its radio resources, and its management capability completely separate. There will be some convergence, maybe at the antenna, maybe at the amplifier. Of course, the operators will want to know if they?re getting good KPIs. The goal is that they shouldn?t have to do anything, except if the red light goes on that says the KPIs are bad, so that someone fixes it. The goal is to be able to deploy tens of thousands of projects, without the network operator having to service and maintain all of them. In order to do that, we need each person in the ecosystem to be able to take responsibility, and manage what?s appropriate. That?s going to be done through a centralized cloud capability and lots of virtualization. It?s a one-box, software-defined, single system, where there?s no need, as you scale, to rip and replace infrastructure. That is a huge thing for the enterprise. Anything that?s obtrusive and requires rip-and-replace is really a deal breaker. Both the enterprise and operators know it has to happen as technology evolves, which is why DAS has always been very attractive. DAS is essentially a dumb pipe, so there?s a part of DAS that?s really attractive to an enterprise. There is a part of DAS that?s very unattractive: the cost of the cabling, and the ever-challenging service or core connection. Monica: One issue that comes up all the time is who?s going to pay for this infrastructure ? the equipment and installation? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |84| Ken: I think you?re going to see all models continue to be implemented; however, the one model that you?re going to see become more prevalent is the enterprise spend. The only reason the enterprise, and specifically the Middleprise, doesn?t spend on these solutions now is there?s no guarantee, or there?s no path towards easy connection to the carriers. There?ll be some projects where the carrier will decide that it wants to put capital in, because it has an interest in that project. Third-party owners will continue to grow in this space. Their ROIs will change how they get the revenue and how they operate. And you are correct in asking who pays for all of it. It can be 3PL systems or carriers. Maybe it?s an advertising model. Or it?s that the building owner?s participating, and it?s managing the system. It is going to be a somewhat different model than the typical third-party projects, but all those models will exist, and the technology will just allow operators to bring the costs down, and they?ll be able to tackle projects that are smaller than the typical large venue. Monica: If the enterprise pays for the installation and equipment, it has a stronger position when negotiating with operators. The relationship between the enterprise and the operators is bound to change. Ken: Yes. Some enterprise customers are going to be large enough that they will have someone on staff who will manage some of that. However, there is a large portion of the Middleprise that will need someone else to handle the carrier coordination, or at least to get approval to turn on their signal. Those companies may ask a third-party system integrator or contractor that has an existing working relationship with an operator. The players will stay very similar, but we?re going to be able to engage projects that just weren?t feasible in the past, and that?s really the goal, opening up the Middleprise market. When this happens, the ecosystem will have to evolve to meet Middleprise requirements. The operators will also evolve, because they?re looking to grow their services and revenue base from the users. Additionally, system integrators will expand their offer to the Middleprise, and they too will get smarter about process and their options to deploy these systems, as soon as they?re more capable and the business models are ready. Monica: This reflects the increasing needs of the enterprise. The enterprise is willing to pay, because it has bigger needs. Ken: In the Middleprise, lack of voice coverage was a big problem. Today it is still an issue for many venues and properties. However, many things are migrating towards database architectures, and so now it?s more of a mobility play. As PBXs start to go away, enterprises see the need to enable everyone?s technology and everyone?s service provider. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |85| Middleprise customers tell us they would like all operators to have the opportunity to become part of the solution. If they have to choose, they?ll pick the bigger ones, but ultimately they don?t want to leave out anyone. The system not only needs to be ready, out of the box, to have all operators connect, but all the operators need to understand that they must be willing to communicate and work with those smaller projects. Monica: Do you think mobile operators are getting more sensitive and more open to the needs of the Middleprise? Ken: Absolutely. Network operators recognize that they need solutions, so they need technology. They recognize they need business plans to be able to provide better in-building service. The network operators are absolutely clamoring for better solutions to allow them keep their Middleprise customers happy. If that means they have to supply a system where the other operators potentially can connect, that?s fine. It?s going to be a question of who?s first. In that respect, operators will be able to expand their Middleprise presence. They may not provide capital, but they may provide backhaul, or better customer service in that particular project. They?re going to be fighting for their piece of that Middleprise. Monica: How important is it to get virtualization in the access network? And what will we put in the cloud, and what will be distributed to the edge instead? Ken: We believe that the more we can put in the cloud, the better. The more we can provide to the network operator from our cloud at a neutral location, the better. The less often a network operator has to roll a truck to a customer?s site, go into the customer?s building and work on things in the building, the better. Never having to physically go to the customer?s site is the ultimate goal. Network virtualization and SDN are critical. You have an intermediary that is aggregating and providing that service to the network operator so operator can aggregate tens of thousands of projects all over the US without having to be able to manage every one of those properties. It becomes a much more manageable proposition to network operators and becomes very valuable, but they haven?t been able to do that up until now. It is only in the last few years that we?re getting to the point where network operators are able to work with a multitude of software vendors for the virtualization of their network, and able to add capabilities and open up their core to new models and new ways of doing business. That is the enabler. Monica: Another thing I want to ask you about is public safety and indoor coverage. Ken: It is something that?s often forgotten. You have two schools of thought out there. You have those who are focused on the commercial cellular side of in-building, and the fact that the public relies on their smartphones to ensure their safety. Then you have a group of people who focus on public safety, specifically the first responder communications, because it is a real problem, one that SOLiD recognizes as a public imperative. I believe the in-building systems and the systems that SOLiD produces will ultimately be able to solve for both of those needs. They may be two different systems. They may use separate cables, but they can be managed by one cloud. Regardless of how they go together, the enterprise is going to require that the provider of the solution be able to put it all together as one system regardless of what the code requires for certain cables and certain systems. In- building public safety codes are rapidly becoming requirements, albeit almost randomly across the country and at varying levels of requirements based on local authority code adoption plans. Any system in the building needs to be able to support those public safety bands in the future. It can?t continue to be two separate systems from a management and an overall maintenance perspective. When you think about it, wireless communication is safety. A 911 call is a voice call, but there?s also data associated with it ? critical first-person information regarding the emergency, plus there is location technology. By the way, enterprises nowadays require that the 911 system work to code and be compliant, but they also are looking for location. They want to be able to know where the people are in the building for safety purposes. Depending on where people are, location is a huge issue in public safety, as well as a potential revenue producer because of the need to know REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |86| where your customers are in a building. There?s a lot of opportunity for location ? but also a lot of undiscussed privacy issues that have to be resolved. From a public safety perspective, knowing the location of the device is a no-brainer. If there?s a device in the building, it may not have a person with it, but we need to know where all the devices are. The great thing about smartphones is that people rarely let them go. Monica: How are we going to change the way we densify networks in the future? Ken: High-frequency bands in 5G are going to become critical. This is important for in-building wireless infrastructure, which means the Middleprise gets even more important, because there?s more infrastructure that may need to go in a building. You might have an antenna on a conference table, but it provides multi-gigabit speeds at that little spot. It all connects back to the same gateway core. It?s critical that the solution can scale to do all these things, and that?s why a software-defined architecture is critical. We don?t know exactly how the protocol?s going to work and how that?s going to function, but it?s going to be very micro-hotspot focused when you?re talking about those millimeter-wave technologies. Ideally, you?d like to work in lower-frequency bands so you can deal with better propagation, but the millimeter-wave-frequency bands of 5G are going to be absolutely critical. For example, in places like hospitals, where you have extreme data requirements, you?re going to see micro-hotspots, where you?re going to utilize those frequencies on a very localized basis to solve high-capacity data needs. You?re not going to try to propagate that through 300 feet of walls. You?re going to have to be very localized that way, which comes back to infrastructure. If you?re using fiber and Cat cables, the infrastructure has to be something you can constantly add to, just like Wi-Fi. Wi-Fi networks today are continuously being optimized. They?re adding more locations, more access points. It?s no different for licensed bands, either. There?s no reason why you shouldn?t be able to continue to add services as you go, which means that the network operator?s going to be looking for ways to make that happen. Ideally I think network operators are going to get more involved with supplying pipes to the building, and dare I say, there?s going to come a time when potentially an enterprise deploys a large system that simply connects to that pipe. Essentially, you may get to a quasi-roaming situation, where if the building owner is paying for the pipe and a device comes into the building and it uses a lot of high-speed data in those micro- hotspots, there may be a back-charge agreement that compensates the in-building network owner for the use of the network by that carrier?s subscriber. It may become second nature for the network operator to have these micro-agreements for each enterprise. Agreements where they can handle those users that go on the system, without having to fund the building deployment and manage the system. That ecosystem ideally would allow them to get incremental revenue that they wouldn?t be able to get if they didn?t invest in the whole system. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |87| About SOLiD SOLiD helps people stay connected and safe in a rapidly-changing world through a portfolio of RF Amplifier, RF Radio and Optical Transport solutions. SOLiD enables indoor and outdoor cellular and public-safety communications at some of the world?s best-known and most challenging venues including leading hospitals; professional and college sports venues; government, university and Fortune 500 corporate buildings and campuses; international airports and metropolitan subways; and other high-profile sites. For further information on SOLiD DAS, Backhaul and Fronthaul solutions, go to or call 888-409-9997. About Ken Sandfeld As Executive Vice President, Ken Sandfeld leads the overall sales and product strategy activities for SOLiD?s portfolio of network densification solutions. Ken possesses over 17 years of experience in the wireless infrastructure industry and is passionate about bringing innovative technologies to market. Prior to his current leadership role, Ken held management positions at MobileAccess, Remec, Spectrian and Zyfer. Today Ken is focused on bringing SOLiD?s leapfrog technologies out of incubation and into the market to solve some of the industry?s biggest problems. Those areas include high-efficiency amplifiers for indoor and outdoor small cell applications as well as low-cost DWDM tunable optical solutions for the Enterprise and Wireless Operator markets. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |88| Profile SpiderCloud Wireless SpiderCloud has been a forerunner in the enterprise small-cell indoor market with its enterprise RAN, or E-RAN, solution. Initially E-RAN used 3G spectrum; now it supports any combination of 3G and 4G, as well as carrier aggregation. SpiderCloud is currently developing new products based on unlicensed LTE and 5G. SpiderCloud E-RAN uses macro spectrum (in a co- channel deployment) or a separate band to provide better indoor coverage and higher capacity for voice, video and other data traffic. The E-RAN system has two elements: 3G and/or 4G Radio Nodes (i.e., small cells) installed throughout the building; and a Services Node, a small-cell controller that manages up to 100 Radio Nodes in a building up to 1.5 million sq ft in size and links to the core network. According to SpiderCloud, a system of 100 Radio Nodes can support 100,000?s of data sessions and handoffs involving thousands of users; 32 concurrent 3G calls; and 64 active LTE connections at 150 Mbps. In early deployments with Verizon in the US, SpiderCloud reported that, after turning on an E- RAN network, the average number of connected users in the macro network dropped by 45%, freeing macro resources for subscribers outside the venue. Services Nodes configure and optimize Radio Nodes with SON, manage mobile access, and monitor QoE and performance. They are linked to Radio Nodes via Ethernet connections that the operator can install in the building or that are shared with the enterprise LAN. In large venues, the Services Node is typically installed on the premises. In smaller venues, it can be remotely installed in the operator?s data center in a C-RAN topology. The E-RAN topology accommodates MEC functionality, to support enterprise applications that benefit from local caching and traffic management. SpiderCloud is working to support LTE in the 5 GHz unlicensed band, through LTE-U, LAA and MulteFire. Unlike LTE-U and LAA, MulteFire does not require a licensed band to anchor transmission, so it will strengthen the neutral-host model in venues where multi-operator support is required. SpiderCloud also supports the use of Authorized Shared Spectrum (ASA), which fits well neutral-host and private LTE deployments. Beyond the walls of the enterprise, SpiderCloud offers SpiderNet, a centralized configuration, fault and performance management system that enables mobile operators to manage multiple E-RAN locations. SpiderNet is based on Broadband Forum?s TR-069, and uses IPSec tunnels to connect to the Services Nodes at the customer premises. Northbound, SpiderNet is integrated with the operator?s core support system through NBIs. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |89| SpiderCloud Wireless Making densification in the enterprise affordable A conversation with Art King, Director of Enterprise Services and Technologies, SpiderCloud Wireless Monica Paolini: In our conversation with SpiderCloud, I talked to Art King, Director of Enterprise Services and Technologies, about the growth in indoor cellular coverage in the enterprise. Art, can you tell us what SpiderCloud Wireless is doing to improve coverage and capacity in the enterprise, and what you?re doing personally in this context? Art King: SpiderCloud Wireless builds indoor cellular systems. We call it the Enterprise RAN. It?s a small-cell technology with Ethernet in the fronthaul within the office building, and Radio Nodes distributed through the building. Its footprint is very similar to the one you?d see in a contemporary Wi-Fi network. We have the Services Node in the telecom heart of the building. It coordinates the cloud of radios and then ties back to the mobile core via high-capacity IP backhaul. My background is in the enterprise space. I got to learn more about the wild world of cellular over the last three years. I do the marketing, evangelization, a lot of writing and a lot of the public-facing activities for SpiderCloud, and I get to interact a lot with both our customers and our engineering organization, and the analyst community and the press. Monica: It may be worth giving a bit of historical introduction, because enterprise plays a major role in the client base of any mobile operator, and yet that segment has been somewhat neglected in terms of indoor coverage. How do you see that evolving? Art: The enterprise hasn?t been neglected, per se. There was a lack of cost-effective technology to address buildings of maybe under about half a million sq ft. Within the higher end, there are quite a few buildings with DAS infrastructure, but a lot of buildings are too small for the fixed-costs to work that DAS entails from a business perspective, for both the operator and the customer. Small cells are opening up the total addressable market to include smaller office buildings that just weren?t available in the past for coverage and capacity improvements. In the DAS model, you build a big wideband antenna through a building and then plug base stations into it. That model does not work for smaller buildings. We?re bringing technology to address the unmet needs of the subscriber buildings from 50,000 to half a million sq ft. Monica: That?s a huge market. We always hear about stadiums and big campuses, which are the first targets, but then as you go down in size, it?s like a pyramid. You have many more buildings, but they are smaller and, until recently, more difficult to cover from a technology and financial point of view. Now we have the technology. How can small cells address the smaller-venue market, specifically? Art: With small cells, you?ve got essentially standard 3GPP cellular technology, but you?re talking, let?s say, a 10,000 sq ft footprint. In the case of Verizon?s deployment that we are implementing, we are reusing the 30 MHz in the LTE band 4/13. By reusing 30 MHz over and over again in the same building, you get a lot of spectral reuse and extremely high capacity, because instead of having that spread out over X sq m, it sits over only 10,000 sq ft. It changes the spectrum needs and allows operators to do a lot of the things they have been struggling with, by making the cell radius extremely small. Monica: In the case of Verizon, you increase the efficiency of the spectrum asset by spectrum reuse. How do you achieve that? Art: We leverage standard cellular technology. Cells were designed to interfere and have cell edges. It?s just the nature of the technology. We?ve built a lot of intellectual property around our platform to enable a better experience for the device owners. At the end of the day, the acid test from the operator community is really meeting KPIs. I don?t have a PhD in engineering, so the nuance of how it?s really done is beyond me, but the KPIs and the REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |90| satisfaction of both the enterprise customers and the operators of the technology are the core message. We can tell through customer satisfaction that we have solved a lot of these problems. A huge amount of automation has been added in the SON, the self-organization, self-optimizing software in our Services Node that coordinates the cloud of radios. With SON, the network keeps itself tuned and aligned and in harmony with the macro network in the outside world. Monica: By making it possible for the subscribers within the enterprise to use the local network, you also offload the macro network. That means that the macro resources are free to be used in the wide area. How does the combination of indoor access and outdoor offload bring value to operators? Art: Indoor and outdoor coverage were always looked at as two parallel things. That?s been one of the discoveries ? perhaps not a discovery so much, but it?s been an internalized change in thinking in some of the RF engineering groups ? that indoor and outdoor infrastructure nodes complement each other. When we started seeing indoor systems drive a drop in macro usage by 50%, light bulbs started going on, where people started thinking about doing holistic engineering. When you look at a macro upgrade, you start looking at the dollars and saying, ?That enterprise building right there generates a hotspot in the macro. There?s a thousand people there. What?s the cost of doing the macro upgrade versus offloading them to a small-cell infrastructure and getting them off the outdoor network?? You?re seeing the emergence of densification not only as a capacity and performance move, but also as a way to manage your spend on the outdoor network at the same time. Monica: The change in performance with the offload has an impact on the business case. To date, the business models for indoor coverage have been difficult, because it?s unclear who?s going to pay for the infrastructure ? the enterprise or the operator. Art: We?re seeing both. We?re seeing operators that are saying, ?We will certify and allow SpiderCloud to be connected to our network. Any reseller or enterprise that wants to build out a network ? as long as it?s done to our specifications and by one of our system integrators that will do a sanctioned, high-KPI installation ? go for it.? There are other operators that are saying, ?We want to build and manage all the pieces.? That obviously has its own capital impact and business process impact. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |91| One big issue with releasing the reins of control is installation or surprise installation might cause channel interference with the macro. The bigger picture that is emerging is that as operators have fewer concerns about co-channel interference and more experience in managing it, they start becoming more comfortable with saying, ?Yeah, let?s have the installations happen more freely, because we know that the technology doesn?t interfere with the outdoor network.? RF engineers naturally start conservatively, because they are held accountable for the KPIs and the performance of the network within their geographies. I understand their concerns, but over time, things start relaxing to where you have the ability to sell to the enterprise and fulfill its requirements. There?s less of a concern about interference on the outdoor network. Monica: Now there?s a lot of talk of neutral host arrangements. Who do you see as the emerging entities in the middle that facilitate these neutral hosts models? Art: You?ve got the large entities like ExteNet, Crown Castle, American Tower, and a lot of the traditional tower companies that are buzzing to do small cells. I have seen host-neutral Ethernets being proposed, where you can plug in small cells and, because they?re being installed above the ceiling, there are no aesthetic issues with multiple radios. We?ve also seen enterprises that are basically saying, ?We need cellular service indoors now. What we?re going to do is to converge on one mobile operator. As part of our contract with that operator, we are going to request an allowance for small cells to light buildings where the performance isn?t satisfying our business users.? You?re seeing both people talking about host neutral, in the context of MulteFire in the future, but also enterprises that are saying, ?I know I can?t get that now, but if I converge on to one operator and manage my contract with them, I can satisfy my business people.? Monica: You mentioned MulteFire. That?s an interesting development in the densification universe. There is LTE-U, unlicensed, LAA, LWA, MulteFire. They all use the unlicensed 5 GHz band, and that tells you is that the unlicensed is of great interest to mobile operators, especially in indoor environments. What?s your view on these solutions? Art: Licensed bands are running out of steam. You don?t have enough spectrum to keep up with the downlink utilization by the customers. You added LAA to boost that downlink capacity in the unlicensed spectrum. Beyond that, with MulteFire, you?re operating both uplink and downlink inside the unlicensed spectrum in a friendly manner, without stopping Wi-Fi. Or if you?re operating it in the 3.5 GHz spectrum, you avoid the issue completely. It?s a great way to solve the neutral-host problem. Instead of building the wideband antenna and doing base stations, you converge on the same piece of spectrum and you converge on the same access methods of the spectrum. MulteFire is being engineered to live in a contention-based environment, where you can REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |92| have multiple MulteFire instances running in the same piece of spectrum, but you can also have a MulteFire single infrastructure that connects to multiple mobile cores. Why is 5 GHz so interesting? It?s a planetary band. Imagine if every UE in the world had a 5 GHz radio and MulteFire and it was available around the planet. It would solve the indoor problem for the world in one equation. That?s obviously recklessly optimistic and forward looking, but you can see the end game being a great simplification of indoor infrastructure. Monica: Having the same infrastructure shared by operators and fully integrated with their network makes it easier to manage for operators. It allows a more efficient use of the spectrum at the access level, but at the same time, it may look similar to Wi-Fi. Art: No, it?s not competitive. In the enterprise it is complementary ? envision the yin-and-yang circle. You?ve got Wi-Fi and you?ve got cellular. One of our enterprise advisers said very clearly, ?I don?t want to be a Wi-Fi provider. I want to be a wireless provider.? He was very focused on satisfying both kinds of wireless for his business people because they were pushing hard for full service on all pieces of technology. In environments like the medical one, where you?re wildly overloaded in your Wi-Fi infrastructure, they?re looking to unload Wi-Fi by getting mobile devices off of Wi-Fi. Monica: From the subscriber perspective, wireless access from the device is the rule today. The question is what technology the subscriber uses. Subscribers don?t care, but as a vendor, an enterprise or an operator, you just have to find new ways to meet that demand. As we get up to 5G, and even before 5G, there is a lot of talk of using different bands, all the way to 60 GHz to 70 GHz, or 80 GHz. What is the scope for those bands with much more limited coverage for indoor coverage? Art: What we?re hearing on the product management side of our organization, from the CTO community, is that the operator community is looking at sub-6 GHz being indoor, and the very high-millimeter waves are going to be outdoor solutions. They believe that what?s going on indoors right now with under-6 GHz, because of just the sheer cost of building wireless access points at a microwave frequency, and having to put a huge amount of them into cabling, it blows up the business case. Sub-6 GHz, because it can generally propagate through walls and has decent indoor characteristics, will continue to be the direction, with the very high frequencies being more of an outdoor solution. Monica: The 3.5 GHz band is going to be a major opportunity for indoor coverage. Art: Yeah, definitely. Without any co-channel interference in the 3.5 GHz, when you hand in, you hand in to a completely different frequency. You?re not worried about the outdoor interference. Monica: A new development is Mobile Edge Computing or MEC, which allows you push core functionality to the edge. Many enterprise applications and a lot of content is tied to the venue location. Is MEC going to be relevant to the enterprise? Art: Yes. It could potentially be relevant in the future, as enterprises buy their own RAN equipment. Right now MEC is going to be operator-controlled infrastructure, because the RAN is controlled by the operator. When MEC becomes relevant to enterprises ? when they can buy a box from a Cisco or an HP, and bolt it into a rack and connect ? it could start being very interesting from the enterprise perspective. We?re seeing plenty of traction and business interest right now with MEC. In the context of what we?re doing, MEC is inserted in the S1 link between the RAN equipment and the core. That can be either through a virtual machine, where we pass the traffic up to the VM and then back to the core, or in an external box. We?ve seen MEC being used both ways. We?ve done quite a bit of prototyping with various software vendors, but the people who are in the lead are looking at the holistic operating environment, the maintenance, the patching, everything necessary to run the whole life cycle of MEC. These folks have thought through what are the killer apps that will justify deconstructing an application out of a cloud data center into the mobile edge. MEC isn?t a data center at the edge of the cellular network. It is going to be a purpose-built environment that has business value being at the edge. It isn?t put there just because you had some computing capacity sitting in an enterprise rack. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |93| Monica: What are the enterprise applications for MEC? Art: We?ve seen caching, local breakout, and a number of applications around the unified communications integration, so that a lot of the native infrastructure on a mobile device can be used with the enterprise infrastructure. One of the funny things is that it drags the network behind it. There are retailers in the bricks-and- mortar space that want to go to a wireless point- of-sale on tablets and mobile devices within their stores. They?re seeking clean spectrum to operate in instead of fighting in the mall with all the Wi-Fi SSIDs and all the adjacent shops and their wireless APs. There are high-end retailers that are looking at this: ?How can I move all these devices to LTE and get out of the traffic jam that I?m in right now, that can cause me to not be able to complete a sale and have to go to a wired cash register because the iPad stops working when I am trying to take a customer order?? Monica: At the same time, all those communications are local, in the sense that they are within the premises, right? Art: Yeah. I was in a situation where a hospital was saying that from a HIPAA perspective, they want to use the LTE, but they can?t loop that customer data out of the hospital through the mobile core and back to the tablet, because of HIPAA regulations. Whether or not that?s a misreading of the situation, they were very clear that they had to keep that data in-house. They felt it was imperative to do it. It was a hard requirement. They were saying, ?How do I do private LTE? How do I do it on the operator?s LTE network, but break that traffic out and send it to my data center inside my building?? Monica: Actually, that reminds me of another issue about regulation: safety, security, emergency calls. How do you deal with that when you are in an indoor environment? Art: For our technology, the cell size and what we?re doing with our cells, each cell has its own ECGI. It?s very identifiable from an LTE perspective. When you look at average cell spacing, I would say a hundred ft between cells, we?re very much able to assist an operator in meeting the FCC requirement that a call must be located within 50 m of the person that generated the emergency call. The ECGI and the information that the installer sets when the radio is installed ? this identifies what floor, what zone on the floor ? and provides what the FCC calls a dispatchable location, so that emergency services calls can get within the distance requirement of the FCC. Monica: What are you working on over the next five years or so at SpiderCloud? Art: Right now, the big things in the pipeline are the LTE-U trials and the things that are going on with Verizon. There?s a huge amount of interest within the operator community that?s in our installed base, because they haven?t built any Wi-Fi infrastructure, and there was a reluctance to build a whole parallel, separate mobile core infrastructure to tie in Wi-Fi authentication. The emergence of LTE-U has generated a lot of interest in the operator community around the world for us. Another thing we have going on is just executing the business plan, and scaling up and helping the operators we have in place get to higher volume, and helping the system integrator channels get more and more efficient and better at deployment. A lot of basic business blocking and tackling to make the machine go. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |94| About SpiderCloud Wireless SpiderCloud Wireless develops breakthrough, small cell network platforms that allow mobile operators to deliver unprecedented cellular coverage, capacity and smart applications to enterprises. SpiderCloud Wireless is based in Milpitas, California and is backed by investors Charles River Ventures, Matrix Partners, Opus Capital, Shasta Ventures and QUALCOMM. For more information, visit and follow SpiderCloud on Twitter About Art King As the Director of Enterprise Services & Technologies at SpiderCloud Wireless, Art leads the development of enterprise services definitions and business case propositions for customers and partners. Art is a Small Cell Forum Board member and a Vice Chair of the Services Working Group. Art was formerly the Mobility/Collaboration lead in Global Architecture for Nike Inc. where he held various global roles over 10 years. Prior to Nike, he led the build out of two multinational engineering and consulting organizations for an IP Services network vendor in the service provider industry. Art holds a BS in Computer Engineering from Portland State University. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |95| III. Operators? interviews REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |96| BT The many roads to densification A conversation with Andy Sutton, Principal Network Architect, BT Monica Paolini: In this conversation with Andy Sutton, Principal Network Architect at BT, we discuss the role that densification has for mobile operators ? and specifically BT in the UK, which has recently become a mobile operator again after the acquisition of EE, which in turn was a joint venture of Orange and T-Mobile. Andy, what is your new role at BT? Andy Sutton: Since BT?s recent acquisition of EE in the UK, I?ve formally transferred into BT?s Chief Architects Office, where I?m responsible for aspects of RAN architecture evolution, along with mobile backhaul architecture and strategy. So I am very heavily focused on the evolution of the existing LTE Advanced network towards LTE Advanced Pro, and working on our future plans for 5G. Monica: Can you give us an update on densification at BT? At EE, you were at the forefront of the densification efforts for a long time. What has changed recently? Andy: From the EE perspective, we had a very dense network from the days of GSM, in as much as we were 1800 MHz?only operators. EE was formed by the merger of Orange and T-Mobile, and both networks operated at 1800 MHz. We took the two 1800 MHz networks, picked the best sites in the portfolio, and had a fairly dense grid to start with in that regard. Of course, then as we added more capacity through 3G and on to 4G, we started to significantly increase the capacity density in the network. Our big focus to date has been around rolling out 4G to the macro cellular network. That?s involved upgrades to add 4G in a number of frequency bands. LTE 1800 is our primary 4G band. In addition, where we need capacity, we?re adding LTE 2600. We?ve already launched carrier aggregation with two carriers. It?s commercially available on the network. We have a third carrier available to roll out this is a second 2600 MHz carrier, therefore enabling three-component CA. Additionally, we?re rolling out 800 MHz where we need it. One, it helps to enhance in-building coverage. Two, it helps to extend geographical coverage as well. Geographical coverage of the UK is incredibly important to us, along with increasing capacity. Once we?ve rolled out onto our existing macro-cell network, then within that macro-cell network we?ve got a lot of what you?d effectively call micro cells. These tend to be fairly short poles with antennas on them, typically 5 to 10 meters high, or installations on the side of shops, office blocks, etc., where we?re really down in the clutter. A lot of these sites were deployed back in GSM days and evolved through 3G to add capacity. In some places we used them to fill in small coverage holes as well. Once you?ve got 4G coverage onto the macro-cell network, and you start to add additional carriers, you can do the same kind of thing on the smaller micro cells. This will further increase an area?s capacity density. Generally, the location of these sites is where demand is, because they were deployed for that demand during the days of 2G and/or 3G. As a result of that, demand tends to grow in the same kinds of areas, in the main. So, really good positioning in that regard. Monica: What?s a micro cell compared to a small cell? Andy: Typically, in our network a micro cell uses macro-cell-type equipment. It?s generally got a small cabinet at the bottom of a lamp post, or it is inside a building with the antennas on the outside, but, generally, the microcell has a much lower output power than the equipment is capable of. So it?s covering a very small area. It could be a smaller version of that macro-cell base station in certain cases. I consider a small cell to be a freestanding, small unit that can be mounted in its entirety on a lamp post that likely contains both the antenna system and the radio, with extremely low power ? 1 to 5 watts, probably in most cases towards the lower end of that scale ? and that would cover a small area by design. Today, these systems tend to be a single operator?s, quite often a single RF carrier. We need the ability to scale these solutions, certainly to support carrier aggregation, to match the capability we?re putting into the macro-cell layer now. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |97| What we don?t want to do, of course, is hand users into a small-cell layer for capacity benefits, and find that we?re restricting the service and the performance, which will impact the overall average network performance of the wide area network. What we want to do is invest in small cells that allow us to increase the average experience, be that data rate, reliability, low latency, etc. A small- cell layer has to be an answer to our problems and not something that?s going to restrict our ability to enhance the quality of the experience. Monica: Do micro cells have a single sector? Andy: Not necessarily. They can be one, two, or three cell sectors, depending on the configuration. If they are on a lamp pole, for example, they could well have three cell sectors. In most cases, it would generally just be a single cell sector?s worth of equipment ? not in every case, but in many cases. Therefore, they may go through a splitter to multiple antennae for covering, maybe, multiple directions from a particular building. Or it could be fully sectorized, or it could be a single stack of carriers sharing antennas. Monica: And do micro cells share the spectrum with macro cells? Andy: Yes, all the same bands, effectively, planned as part of the macro-cell network in that regard. We?re not doing a lot to differentiate between the layers. We do use certain parameters, such as hysteresis, for example, where you have to dwell on the micro cell for a certain period of time before you hand in to it. Again, that?s not on every micro cell. It depends on the use case in the deployment scenario. Monica: How do you move from micro cells to small cells? Andy: The next phase is to really understand how we deploy ever smaller cells, and tie that in, also, with our approach to in-building coverage. If a huge amount of data is generated in-building, and we can manage that capacity within the building, then of course it?s going to reduce the demand on the external macro network. Currently we?re considering the optimal strategy for balancing growth in external network capacity with managing in-building coverage to remove, effectively, capacity demand at the source, therefore helping us to balance the overall network. That also allows us to work towards a more energy-efficient networks as well. In areas of high in-building demand, rather than transmitting everything from outside in, we can manage that capacity more efficiently with in- building solutions. Monica: What challenges do you face as you move indoors? Andy: Among the challenges we foresee, site acquisition is always one that operators have. We need to develop new strategic partnerships. We also need to understand what new business models are available for both external and internal deployments. I think we?re definitely moving into a period where, rather than mobile operators pushing mobile communications on people, there?s a real pull now from the general public, from enterprise and businesses, from academia, etc., to actually have good-quality coverage and also capacity. New business models should make it simpler to access sites and infrastructure. In addition, of REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |98| course, we need to make sure we can provide backhaul connectivity to these sites. Backhaul is probably the second-biggest change after initial site acquisition. That?s going to require a combination of high-capacity, fiber-based solutions. It?s going to get expensive if we try and run point-to-point fiber everywhere. We?re currently exploring opportunities for the use of PON infrastructure. It could be an evolution of GPON. Something I?m quite keen on is the introduction of WDM PON in the future. With WDM PON, we could have dedicated wavelengths, so we?re not sharing the access between different use cases. Monica: How reliable ? and valuable ? is wireless backhaul? Andy: We have a range of wireless solutions available today for small-cell backhaul, from traditional bands such as 28GHz to wider channels in the millimeter wave bands, including V-band centered around 60GHz. E band equipment is starting to get smaller. I think there?s further opportunity there. It?s still a little big and a little expensive at the moment for the small cell use case. Maybe not so bad as a first hop from macro down, but in terms of distribution, it?s not quite there yet. As we look further forward into the evolution of LTE and the introduction of 5G, we also need to understand what self-backhauling can look like. Today when we talk about self-backhauling, people think about near-non-line-of-sight or non- line-of-sight and LTE frequency bands. But it does not have to be. Monica: How will backhaul and self-backhaul evolve as we move to 5G? Andy: In a 5G timeline, we need to understand what we could do if we took all the various spectrum bands available to us, all the way from sub-6 GHz up to and including the higher millimeter-wave bands that have been discussed as potential radio interface technologies in the future. We need to understand how we could drop a small cell into a particular area in the network, and then have it develop its own backhaul using SON techniques. If we?re going to be using full-dimension MIMO or 3D MIMO on these small cells, then potentially we could provide connectivity, either primary or backup connectivity, via a particular beam between adjacent small-cell base stations, as well. It may well be that we have a primary link that is a point-to-point 60 GHz radio, for example, or a multipoint-to-multipoint system in a lower frequency band. But, actually, if that link were to fail or it needed more capacity, we could have alternative connectivity in the network. Monica: How is densification changing the way you plan and deploy your networks? Andy: We need to think very differently about how we build networks, because, as well as ultra- dense networks, we?re under increasing pressure to build ever more reliable networks ? ultra- reliable networks ? and, of course, ultra-low- latency networks as well. When considering densification, it?s important to overlay a number of other requirements. Do a densification plan. Do an ultra-reliable plan. Do an REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |99| ultra-low-latency plan. Then start to play those off against each other and understand what a single network looks like to meet those varying demands. From a capacity perspective, we?re either adding more sites or more spectrum, or we?re getting better spectrum efficiency. We gained a lot of spectrum efficiency by refarming spectrum from GSM to LTE. Certainly more spectrum?s going to help, and more sites are going to help too. Then you end up with quite a complex arrangement around acquisition and backhaul. The introduction of self-organizing network capability is going to be absolutely key. The challenge I see with SON today is that it tends to be focused on aspects of the RAN or it can do something in the core, it?s not joined up at the network level. Monica: Is network slicing going to make the RAN more efficient? Andy: I?ve not seen anything that?s really lining up behind this concept of slicing as we move through LTE evolution to 5G. If we really want an end-to- end service, we need to ensure that service is available, that capacity is sufficient, that the low- latency specifications ? whatever they happen to be ? are met, and that it is also reliable. If we want to go to multiple nines of reliability or availability, we need to be looking at truly heterogeneous networks with a whole range of technologies. This plays into the idea of using different radio access technologies as well, in both licensed and unlicensed spectrum, and understanding how to get licensed and unlicensed bands to coexist and cooperate. We could couple them very tightly with something like LTE-U or LAA more specifically. There are a whole range of other mechanisms we could potentially use to help the two radio technologies cooperate, as well. There are lots of aspects we need to consider when developing the overall framework of a dense network. If you were just to build an ultra-dense network, you would then have problems overlaying other requirements in the next decade on top of that. You have to factor all that thinking into the conversation quite early on. Monica: You mentioned indoor coverage. Micro cells are mostly outdoors. How is it changing the balance between indoor and outdoor? Andy: Yes, indeed. We?ve got a number of solutions for indoor. Starting from, obviously, large stadiums: England?s National Stadium at Wembley is actually connected by EE. We?ve got a huge installation there: 24 cell sectors and somewhere in the region of 200 antennas. That?s an example of what we are doing at some high end locations, but actually, small cells for in- building includes a mix of pico cells and femtos. Various other femto solutions are being used in a range of enterprise applications where maybe a large DAS system wouldn?t be appropriate. As we?re addressing in-building coverage now in residential premises as well, we have launched not only VoLTE, but also VoWi-Fi. We have Wi-Fi Calling now across a range of devices. If a subscriber has Wi-Fi coverage at home, they can make and receive calls on the Wi-Fi as well. Monica: In the US, DAS seems to be much more popular than anywhere else in the world. What do you think about DAS? Andy: We certainly deploy DAS in large deployments, large stadiums. There are opportunities in large shopping malls. DAS lends itself to shared deployments, where multiple operators want to invest, or where a site provider wants to cooperate with multiple operators and develop a single distribution network around the stadium or shopping mall, for example. Those kinds of mechanisms work pretty well when the alternative is everybody?s trying to co-site all their own small cells around the site. As you get into the smaller businesses, then you tend to be engineering more bespoke solutions based around that enterprise being a customer of yours. In this case, the requirement from this customer is simply to get coverage from your network, in which case DAS is still one of the options. When you get into the smaller businesses, small cells may work micro p or pico cells could be deployed and used with multiple antennas to ensure sufficient coverage within the building, on different floors etc. Monica: You mentioned that DAS lends itself to basically infrastructure sharing so you have multiple operators on the same network. Could we duplicate the model, making some allowances, for small cells? Andy: Yes. The small-cell story is an interesting one. When I mention sharing small cells I?m quite often thinking of the network-sharing agreements REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |100| that we?re starting to see in various places around the world. They?re certainly well established in the UK where you may want multiple operators deploying their own carriers but on a shared piece of infrastructure. So having that flexibility is attractive. The alternative to that is for a third party to deploy small cells, and support multiple operators. That?s a complex situation. How do you get the necessary agreements in place? How do you manage quality of service, rollout priorities, backhaul prioritization, etc.? And then how do you actually do the hand- offs? These models have great potential, and we?re very keen to explore them. Some of the technologies coming to market now are extremely innovative and offer flexibility to support a range of deployment use cases. I guess the question always is, does the operator want to hand over a level of control for the network to a third party, and how equipped are those third parties to take that role on, deliver that carrier-grade support that operators have been doing for many years? Monica: In a neutral-host model, you could have a situation where each operator has his own radio, so you would not have control over the physical infrastructure equipment, but you?d still control the spectrum and the access. Andy: Indeed, absolutely. I would expect that would be the case. We?d deploy our own spectrum assets. The question then is just how many of the parameters in the base station can be optimized on a per-operator basis against that radio spectrum. Again, that ties into the siting, the antenna selection, tilt, behavior, etc. Monica: In the UK you?ve had quite a long history of having third parties working with you. Andy: Indeed. There?s a range of operators. Fixed and mobile operators themselves have a great opportunity to be a third-party neutral host. Developing some of those opportunities is something that, as an industry, we should be considering for sure. That would give the best operational model. We have a range of people who own large numbers of sites, for example, who are actually buying up access to infrastructure. They could potentially take on that roll or work in partnership with mobile network operators or a wholesale service provider. Conversations to date have always been a little challenging as to exactly where the demarcation is and where the operational responsibility is. As our industry matures, everybody realizes that for anybody to progress with these ideas and for everybody to win, we have to find a consensus. We have to find a way of moving this forward. That means we need to be pragmatic in terms of costs, contracts, and return on investments. Monica: With in-building small cells, is there a change in the relationship between mobile operators and the enterprise? Specifically, traditionally the operator owns all the infrastructure, but with most cells Wi-Fi type of an infrastructure, would you expect the enterprise to pay for the equipment and then the mobile operator to operate it, or is it the operator that pays for everything, as traditionally done? Andy: Traditionally it?s certainly been the operator that pays, but I think we?re all open to new models now. It depends upon the enterprise?s aspiration. If the enterprise is a landlord wanting to guarantee good-quality coverage in the building to attract tenants, then clearly it?s in their best interest for them to be making sure that happens. The best way to do that is to fund an installation, in part or entirely. There are other approaches, of course, whereby if an enterprise is investing in Wi-Fi, the operator could deliver a solution that supports VoWi-Fi. Then that could be part of the agreement ? that the operator provides that service, makes sure all the devices are capable, etc., and then the enterprise can make use of the Wi-Fi service within the building for voice and data services. There is a range of different models we can consider here. It depends upon the use case and the enterprises themselves. We get very different ranges and requests. Monica: What about LTE unlicensed? How is that going to play out in this kind of environment? Andy: In the UK, we wouldn?t necessarily expect LTE-U, but certainly LAA is something of interest. We?re very keen to understand how that will operate, how it will coexist properly with Wi-Fi. We?ve got to coexist within the established Wi-Fi band. Certainly, having the ability to call up a 40 MHz LAA channel in the traditional Wi-Fi band, the ISM REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |101| bands around 5 GHz, would give a huge boost in downlink capacity. So, using that as a supplementary downlink and at 5 GHz, that really lends itself to being used in-building, of course. Obviously, there are going to be restrictions on the propagation characteristics of that particular band. They?re going to be difficult to match with other cellular bands. During trials, both in-building and externally, it would be interesting to understand exactly what can be achieved. Certainly that?s the kind of thing that?s in our strategic plan. Monica: What do you think about LWA? Andy: LWA could be an easier alternative in some regards. What we?re really waiting on at the moment is chipsets to support this in a range of end devices so we can start doing some testing, and really understand what the options are. We haven?t nailed down one favorite at the moment, and I suspect we?d probably end up with a range of different hybrids of licensed and unlicensed that meet different use cases. Monica: What about millimeter-wave bands? You mentioned the millimeter wave for backhaul. What about for access? Andy: With the current and projected traffic volume, we will need millimeter-wave radio interfaces at some point, certainly high-centimeter wave or millimeter wave. The question is, when do we really need it? There?s additional spectrum in the sub-6 GHz bands that will be made available in the near future, as well as a number of other bands that will be made available over the next, say, five years. There?s a lot more spectrum coming in those bands. I guess the question is how big do you make a site, compared with how many sites do you deploy? You could, for example, build a large number of small cells with an amount of spectrum on them, or you could continue to build out sites you have today and expand them with more spectrum assets, more capability. There are some practical site design constraints that limit what you can build, how far you can develop those sites. There are, of course, regulations around EMF that would restrict the total power you could put out of those sites. What we really need to understand as part of the millimeter-wave discussion is what does a dense network of sub-6 GHz radio base stations look like? If we have smart antennas, we?ve got 3D beamforming, for example. Then we?re going to get a step increase in spectral efficiency and area capacity density. How far does that get us? Something we?re working on at the moment is to understand that evolution of area capacity density. When we do move into the millimeter-wave bands, then we?re probably looking at another level of densification to support sites that maybe have a cell radius of 100 to 250 m. Ensuring a robust radio interface connection in the higher bands is a challenge and may involve a range of techniques. Such techniques would likely involve dual connectivity and tight coupling or coordination between cells in the same and different layers of the network. At the moment, most of the expertise in these higher-frequency bands is in the fixed-link world, so it?s the people working on millimeter wave for point-to-point, point-to-multipoint, multipoint-to- multipoint systems. Integrating this into a radio base station with all the associated multi-layer radio resource management in a heterogeneous network, and also putting that into a UE with a decent antenna, is going to be a bit of a challenge. Of course, for it to work as radio access, it?s going to have to be very tightly coupled with the lower- frequency bands as well. It?s very likely the lower- frequency bands will provide the control planes and an amount of user-plane capacity. Thus the bulk of the user plane could be pushed into a millimeter wave radio access layer. Monica: How about using a C-RAN type of approach to increase densification? How big a challenge are the latency and capacity requirements on the fronthaul? Andy: The challenge for C-RAN today, of course, is the capacity requirements on CPRI?s fronthaul. Backhaul for a 20 MHz 2x2 MIMO FDD carrier would be typically 150 to 180 Mbps. With fronthaul, you suddenly jump to approximately 2.5 Gbps to do the same thing with CPRI. That starts to burn up a lot of fiber and a lot of expense. So how scalable is that for your entire network? Well, given the fixed relationship between fronthaul today with CPRI, and a, the spectrum bandwidth that you use, and b, the number of antennas you deploy, that really plays against wideband radio channels with ever more REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |102| carrier aggregation. It also plays against massive MIMO as well. I think the problem is scaling CPRI as we know it today. I am encouraged, nonetheless, by the amount of work that?s ongoing, looking at alternative functional splits between the radio unit and digital unit. As soon as you remove that need to split, as you would do in conventional C-RAN, and start to move a little further up the radio stack, we can start to offer some alternatives, something around the MAC layer ? split MAC for example ? or alternatively, split just before PDCP. Of course, the higher up that radio stack you go, the less optimal the radio coordination will be. There are still a lot of benefits to be had. Maybe, the ability to change that split dynamically between, possibly, sometimes the MAC layer, sometimes the PDCP layer will give you a lot of flexibility to respond to different radio environments and radio channel conditions. Certainly, in some environments, pure CPRI may work, but I think that?s going to be restricted to stadiums and other environments like that. I think really we need an alternative functional split we can carry over, an Ethernet-based backhaul that?s going to have some benefits in the radio network. Actually, it?s going to be more backhaul friendly. The performance requirements are not going to be as stringent as they are in CPRI, and the capacity requirements, most certainly not. Monica: How important is synchronization in a multi-layer network? What level of synchronization do you need for enhanced inter- cell interference coordination (eICIC), TDD or eMBMS? Andy: The phase synchronization requirement is typically stated to be around plus or minus 1.5 ?s. As an industry, we?ve made good progress in understanding that, and developing ways to deliver this in a robust manner, and support that level of phase alignment which we provide increasingly, in addition to the standard frequency synchronization. We need to understand, as LTE evolves and 5G is introduced, where those requirements are likely to go. Again, if we make it much tighter, we?re going to add extra cost complexity to networks. We need to be very careful about some of the decisions we make about the level of coordination and time alignment we need to achieve, so we don?t create a huge cost and operational overhead for operators. Monica: This is an additional dimension when you look at the tradeoff between cost and performance. Andy: Absolutely. That feeds into the discussion around SON as well. Given the number of base stations we?re going to have and the complexity of those base stations, we really do need to start automating more and more of these processes. We need to be making use of machine learning, so we can start to make more intelligent decisions about optimizing the network in real time. Monica: Optimizing and basically extracting much more from what you have already, rather than build. First, extract as much as you can, and then if it?s not enough, build more. Traditionally, it?s like a brute force. You try to send as much data as you can. The old networks didn?t give you a lot of opportunity for choice. Andy: Absolutely. That optimization, traditionally, has been something operators have done end- to-end on the network. As a wider industry, we need to be talking more about what top-to-bottom optimization looks like as well. What kind of applications are we developing, and what protocols do they run over? A perfect example is the fact that over 50% of the traffic on the EE 4G network is video. Of course, when video was first introduced to the internet, it ran over UDP. Now, it runs over TCP. That subtle change from UDP to TCP has a massive impact on the efficiency of network operations. We need to look at top-to-bottom protocol-stack optimization, and understand how we?re going to evolve that protocol stack, over time, to a protocol architecture that delivers the optimal user experience for end customers, network operators, and application developers. What I like to think about in this context is not just bps/Hz, but the application bps/Hz, as a true measure of network efficiency. In terms of the applications? efficiency and the experience you get as a result of that, and then how that ties into the cost of building, operating, and scaling networks. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |103| About BT BT is one of the world?s leading communications services companies, serving the needs of customers in the UK and across 180 countries worldwide. Our main activities are the provision of fixed-line services, broadband, mobile and TV products and services as well as networked IT services. In the UK we are a leading communications services provider, selling products and services to consumers, small and medium sized enterprises and the public sector. We also sell wholesale products and services to communications providers in the UK and around the world. Globally, we supply managed networked IT services to multinational corporations, domestic businesses and national and local government organizations. About Andy Sutton Professor Andy Sutton is a telecommunications network architect and designer with 30 years of industry experience. At BT, he is currently responsible for RAN architecture evolution and mobile backhaul architecture and strategy. Andy became part of BT after the acquisition of EE, having worked for EE since the merger of Orange UK and T-Mobile UK in 2010. Andy previously worked for Orange having returned to the company in March 2007 to take up the role of Principal Transport Network Design Consultant, he spent the previous two years working for 3UK, initially as a WAN Specialist and then as Lead Network Architect. Prior to 3, Andy was with Orange for 12 years and prior to that, he worked for Mercury Communications on fixed network transmission, switching and synchronisation systems. Andy is a Chartered Engineer (CEng), Fellow of the Institution of Engineering and Technology (FIET) and Fellow of the British Computer Society (FBCS), he contributes to the MEF (Metro Ethernet Forum) and NGMN (Next Generation Mobile Networks) Alliance on mobile backhaul topics. Andy is a Visiting Professor with the department of Computing, Science and Engineering at the University of Salford and a Research Mentor at the University of Surrey 5GIC. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |104| DOCOMO Innovations Technology enablers for densification A conversation with Ozgun Bursalioglu, Senior Researcher, DOCOMO Innovations Monica Paolini: Densified networks are not just networks with a higher concentration of access points. They force us to think of network planning and management in a different way. They require and benefit from different technologies and architectures than macro-only networks do. This is the topic of this conversation with Ozgun Bursalioglu, a Senior Researcher at DOCOMO ovations in Palo Alto. Ozgun, what do you see as the major trends among operators as they work towards densification? What?s changing? What needs to be done? Ozgun Bursalioglu: Here at DOCOMO Innovations, we have research activities for 5G and beyond, especially on the PHY layer. Our recent publications mostly focus on massive MIMO, and mmWave-band technologies. As for major trends in densification, first of all, we need to serve many more users all at the same time. You?re talking about increasing multiplexing gains, and this brings the concept of densifying our equipment. And having many more cells coming closer together changes the inter-cell-site dynamics. Remote radio heads, distributed MIMO, and of course massive MIMO are all very important. Monica: We have had MIMO for a long time, but it?s still evolving, with massive MIMO and distributed MIMO. How do you see MIMO evolving within the densification context? Ozgun: Companies and academic researchers see massive MIMO as one of the key technologies to enable all of 5G?s promises. Many people in research have recognized this potential since Thomas Marzetta?s seminal work at Bell Labs. First let?s remember one thing about massive MIMO. With massive MIMO, basically we have lots of antennas compared to the number of streams we are simultaneously serving. That just basically makes the beams we are assigning to different devices very sharp. That means the interference between them is less. That?s great, of course, for densification, because we can hopefully mitigate the interference problem. This all assumes that there is high-quality CSI, or channel state information, available at the transmitter. That is a very important and deep topic for massive MIMO. Monica: It?s taking MIMO to the next stage, and so that should lead to a much more efficient user spectrum. Ozgun: Yes. Also, it has been shown that massive MIMO is very efficient in terms of power. It is the way to go in 5G. With massive MIMO we have to put up all of these many antennas, and in higher- frequency bands, the antenna spacing can be much tighter, and you can pack in lots of antennas into smaller footprints. Monica: Right. Any difference between FDD and TDD for massive MIMO deployments? Ozgun: This is a great question. It is very related to the channel state information that we discussed. In FDD, the base stations send DL pilots to train the antennas for DL transmission. These operations scale by the number of antennas in the traditional way of doing FDD training. Now, if you follow the traditional approach, combining massive MIMO with FDD is not practical. In massive MIMO deployments, TDD becomes more practical, because training for DL can be done through UL pilots. The user sends the pilots, and the base station can train all of its antennas at the same time. The training cost scales in terms of the number of users you are serving. That is, of course, great. We should also mention that, in the FDD case, there has been a lot of great research on doing FDD training with massive MIMO, but it requires a bit more effort. It requires the learning of second- order characteristics of the channel, and it works much better for the macro layer. In short, although there are some other methods that can be considered, TDD with reciprocity- based UL training seems to be the preferred choice right now for massive MIMO. This is the reciprocity of the physical uplink and downlink channels. Of course, this reciprocity from your device to the base station does not hold if the RF chain is REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |105| considered. We have to do some calibration at the base station to take care of this problem. Actually, we and many other people have worked on that, and it is possible. You can do an RF calibration at the base station using signaling between BS antennas without using any collaboration from the UEs. These are all very important points. Monica: I guess it?s becoming feasible because operators are able to optimize the RAN in real time, so they have the information and then they can just use it. Is it making it feasible to deal with the increased complexity of MIMO? Ozgun: You have to calibrate the RF chains of different antennas. All of these antennas can talk to each other and listen to each other?s signal. That way they kind of correct themselves. They align themselves that way. There are some important differences, though. RF calibration happens at a much slower rate than the training for the channel that we require. In that sense, you can do the RF calibration of this alignment between the antennas at the base station, and then you can go ahead and train the channels and serve the users. Monica: What part of this needs to wait for 5G, and what part can be implemented ahead of 5G? Ozgun: Calibrating these antennas, of course, requires time and signaling design. I would say that we may need some standardization effort to reserve this signaling time for calibration. How much time we need depends on the tradeoffs that you are looking for. For the macro base stations, normally you can have very expensive equipment where this calibration is not necessary for a long time, because it is very high-quality hardware. It takes longer for them to get de- tuned. If you have cheaper, more cost-effective devices, you need to calibrate them more often. The other thing is that you?re working with many antennas, so of course it takes more time to calibrate the devices. We are trying to understand what grade of hardware we are going to use, the number of antennas, and what is the best way to do it. Also, there is even calibration between distributed antennas. This is all ongoing work. We have done theoretical research where we have modeled hardware imperfections and come up with algorithms to compensate these. There are also ongoing trials, field experiments done by companies and universities. Monica: There?s a lot of excitement about MIMO, but another topic that?s getting a lot of attention now is millimeter-wave bands. What?s the best way to use that spectrum? Ozgun: There are many ways. People are looking at using it for different aspects, but one way we look at it at DOCOMO Innovations is to increase throughput. It is great in that sense, just because of the huge bandwidth available if you have a good connection. The problem is, getting full coverage with millimeter-wave is much more challenging, because of the propagation conditions. We think it is best to assist the millimeter-wave band layer with the macro layer. DOCOMO has suggested this approach, and called it the phantom-cell concept. It is a split of the control plane and the user plane. You make sure the control plane is in the macro layer, so at least the device is always going to be connected to the nearest macro cell and the control plane information is available. If there is an established connection with the millimeter-wave band, we can get throughput from there. If not, we can always go back to the macro layer. Monica: Right. That?s very important, because you can combine the reliability of coverage from the macro with the increase in capacity from the millimeter-waveband link. Ozgun: There is one more thing. Now we have all these small-cell base stations, remote-radio-heads, and distributed antenna systems. In this case, the user, in theory, does not have to know where the signal comes from. It might just need a unique cell ID that enables the device to connect to any transmission point covering that location. Monica: How does the unique cell ID work with small cells? What are the advantages of this approach? Ozgun: It helps with the handoff procedures. When you densify the network, cells get very close to each other and the number of handoffs grows. Trying to switch from one base station to the next base station takes lots of time. It will have a huge overhead, and we don?t want that. We would want a user device to seamlessly connect in a fluid way to all of the transmission points around it. Now, if you are trying to arrange the connection to a cell every time you realize, REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |106| ?OK, I?m getting a signal from this cell,? it may become a big mess if you do it very often. Instead, with a unique cell ID, you have these joint points around you that are doing transmissions, but somehow you see them as a single point, like a single cell. That helps with saving the time, the training, and of course, eventually the throughput. Monica: That?s an entirely new way to think about cells as a unit. Ozgun: Yes. Now, actually there is a trend towards user-centric approaches. We used to think about base stations and cells, and the users in the cell, right? Then we had macro cell, cell-edge users and all kinds of other problems. There is a trend, especially in the academic research, towards these user-centric approaches. Users can be served by base stations (macro cells, small cells, or DAS). And each user might have a unique set of these base stations that it can connect to, so you don?t necessarily cut and piece your network into cells now. But, again, this architecture needs to be scalable. This architecture needs to be smart so you know which base stations or which points of transmission to assign to this user, and this must be very fast. We do research on these architectures. Monica: Increasing capacity is obviously the first goal, but there is also a need to reduce latency. Because you can have all the capacity you want, but if the latency is high, the service is not good from a user perspective. Latency is becoming more and more important with real-time applications. How can we lower the latency in 5G? Ozgun: There are many things that we want from 5G. Different applications may require lower throughput but very low delay; others may have a high throughput but tolerate higher latency. The delay that we see at the user device, or in a device without a user, such as a machine, is a combination of things. The delay might be because of the application layer, the network layer, or the PHY layer. I prefer to talk about the PHY layer, and an important part of it is coming from the traditional way of training and associating to the base station ? the way the base station sends the pilots, users learn the channels, and the user sends feedback ? all of these. With TDD UL training, which really sits well with massive MIMO, training is immediate: the user sends the pilot, and the base station learns the channel. That saves you a couple milliseconds from the delay perspective. One important thing, again, at the PHY layer, is that as we are going to higher bands, the coherence times get shorter. We need to be very careful about doing these things very fast. Monica: You can densify your network in many ways. You can use DAS, add small cells, or improve the macro layer. What?s the balance there? Ozgun: Among all the things that you said, basically the idea is really to have many more devices and many more antennas. Even when we talk about distributed MIMO, we can actually talk about distributed massive MIMO. If you have already acquired the site for transmission, why just put a single antenna? You could and actually should put many antennas to a site. Also, as you move to higher bands, to indoors, or to hotspot scenarios, you don?t necessarily have these macro-style base station sites anymore that you can control. These new base stations can be anywhere. In terms of capex and opex, you might need to choose cost-effective devices. Although these devices are much cheaper than the corresponding macro ones, you could still benefit from them using smart algorithms ? for example, RF calibration. Another example is that you might want the distributed antenna systems to be synchronized in terms of frequency or timing for coherent transmission. You can do this with a common clock, or maybe with over-the-air synchronization. We need to think about having networks where these things can be adjusted. If the connection to one of them fails, your networks should be smart, to use other available connections again. It?s, again, very important to think not just about size but also the transmission points around the users. If one connection fails, your coverage should not fail. Monica: Preventing failure is possible, because if you have multiple layers, the same mobile device is covered by multiple elements in the network and has the flexibility to choose which elements to connect to. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |107| Ozgun: Also, going back to massive MIMO, because of its very sharp beams, a user device can get data signals from many different points, unlike the macro layer where you are connected to a single base station. Monica: How are the requirements of densification changing or being driven by IoT? Ozgun: In IoT we might have different classes of operation. In one case a device might need to connect to the network very fast. Maybe the connection can have a very low transmission rate, but the speed of getting connected is important. Again, the delay is very important. The events for which these devices might want to connect might be very random, very sporadic, or they might happen simultaneously. I think we need much faster random-access protocols, much faster training for introducing these devices into the networks they want to connect to. Monica: What are the crucial bits in 5G as far as densification is concerned? Ozgun: If you think about it, we used to plan our networks with our base stations, and decide which users connect at which time, right? With the 5G, as I mentioned, connections to some of these stations might be interrupted or there might be a blockage, so you need to be smart in arranging various connections. At the same time, I think a major concern, especially for hotspot areas, is the multiplexing gain. We want to serve many users at the same time. That requires us to train all many of these UEs at the same time. More users trained, more resources in terms of time and frequency are given to the training phase from the transmission phase. It is essential to do these things in a more efficient way, in a way that you can simultaneously train users, instead of training each user one by one (one per pilot dimension). We show that with pilot collision detection and fast user identification, you can overcome this problem. This way you can really make use of massive MIMO ? because otherwise, if you don?t do the training right, you?ll run into pilot contamination or you?ll have to be really conservative and use a large pilot re-use, and that detracts from your densification gains. Monica: In today?s networks, you have different layers, different networks, different access technologies, different bands, and so the question is: how are you going to select which device selects which network? How can we go about it? The subscriber doesn?t want to manually pick a network, but from the network point of view, the operator needs to decide what?s the best way to serve that customer sitting there with that device with some applications that he?s trying to use. Ozgun: You?re highlighting a very important part, which is load balancing, and, with that, user scheduling. It is a very tough problem. In the macro layer it is easier, in the sense that the cells are bigger and you have a larger number of users. Things average out nicely. Going to smaller cells or networks with multiple layers, you?re actually seeing an irregular, maybe an unplanned, network. Of course, the user doesn?t want to choose which ones it connects to. This needs to be automatic. The base station I get my signal from should not just depend on the channel to that base station. It should also depend on whether that base station is overloaded with other users or not. In the current system, the user device decides which base stations to connect to, based just on its channel gain. This system causes overloaded base stations, and that?s what we see in crowded areas. If you can push some of the users, some of the traffic, to the less-used cells, you can increase the overall base station utilization in the network. With massive MIMO, this is possible, because you have these beams that can come to you from different base stations. You should be able to pass the stream from one BS to another one with less load. How do you decide all of these things while you are transmitting in milliseconds? A very important aspect of massive MIMO is that you have channel hardening. That means the throughput you are going to get becomes independent of the instantaneous channel. It becomes independent from the small-scale fading. In a way, the channel hardens. That means the base station can pre-guess, or the operator can guess, the rate that the user will get from a base station. Having this information on a larger time scale than the transmission time scale is valuable. Since the traffic load changes happen much slower, you can optimize your network operations in terms of how to shift traffic between different layers. This optimization can even take into account the properties of the traffic ? for example, applications with different delay tolerance. Channel hardening makes these REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |108| problems simpler, and we see lots of gains. Load balancing will be very important in the future. For example, although the transmission happens at the millisecond level, thanks to channel hardening, ahead of time (on the order of seconds) you can have a pretty good idea of what you?ll get in terms of rate in the next milliseconds. That allows you to be smarter about where to put traffic, and it ties very well with the coordination between millimeter-wave bands and the other bands. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |109| About DOCOMO Innovations DOCOMO Innovations is more than a just an organization for business development and strategic investment. All groups within DOCOMO Innovations work together to realize new applications and services through collaboration with American companies for the next generation of mobile services and beyond. DOCOMO Innovations provides vital innovation to enable the future growth of NTT DOCOMO, Inc. in the Japanese and global markets. DOCOMO Innovations is structured around four key teams, whose initiatives run the gamut from mobile applications all the way down to core networking technologies: Business Development and Investment, Open Services Innovation, Android Product Innovation, and Mobile Network Technology. About Ozgun Bursalioglu Ozgun Y. Bursalioglu is a Senior Researcher at DOCOMO Innovations Inc., working in the area of wireless communications on MIMO techniques and LTE enhancements since 2012. She graduated from the Ming Hsieh Department of Electrical Engineering, University of Southern California, in 2011. Her Ph.D. thesis is on joint source channel coding for multicast and multiple description coding scenarios using rateless codes. Previously she received M.S. and B.S. degrees from University of California, Riverside (2006) and Middle East Technical University (METU), Ankara, Turkey (2004), respectively. She received the best student paper award at the International Conference on Acoustics, Speech and Signal Processing (IEEE ICASSP), in 2006.. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |110| Carolina Panthers DAS and Wi-Fi join forces to keep sports fans happy A conversation with James Hammond, Director of Information Technology, Carolina Panthers, and Kevin Schmonsees, CTO, Beam Wireless Monica Paolini: Stadiums and other sports venues are typically the first targets of densification because of the extremely high usage density during events. Our conversation about wireless coverage at the Bank of America Stadium in Charlotte, North Carolina, is with James Hammond, the Director of Information Technology with the Carolina Panthers, and Kevin Schmonsees, the CTO of Beam Wireless. James, stadiums are one of the best examples in terms of high usage creating a highly challenging environment. Can you give us an introduction about what you do personally and what infrastructure you have in the stadium? James: At Bank of America Stadium, we were faced with a problem over the previous two or three years where our fans were not able to get the connectivity that they expect. At the games, they want to be able to do Twitter, Facebook, they want to take selfies. They want to do all the things they are used to doing with social networking and connectivity in their regular lives. It got to the point where the number of fans trying to get onto social networking and the internet in general was exceeding the capacity of our systems. It didn?t matter whether they were using Wi-Fi or the cellular systems for their data. They weren?t able to get through. That was leading to fan dissatisfaction. At about that point, they hired me ? and one of the reasons was to tackle these problems. As soon as I got to the Carolina Panthers, I started examining the systems that we had in place -- the DAS system for rebroadcasting those cellular signals, as well as the Wi-Fi systems ? and found that they both really were not keeping up with fan demands. They were under-designed for a much smaller user population, making their five-year-old designs obsolete. At that point we decided to bring on new systems, and that meant ripping out and replacing the entire DAS and Wi-Fi infrastructure. Monica: Kevin, what about you? Kevin: Michelle Rhodes and I started Beam Wireless when we saw a gap in the industry where there was frustration amongst venue owners just like the Carolina Panthers. They just don?t have the visibility and control of a DAS inside their venue. What we try to do is provide the consulting ? whether it is design, contracts with carriers, or validation and optimization, to allow them to learn, manage, and have full visibility into a DAS system in their venue. Monica: Before we talk about the technology, let?s talk about the ownership structure. Who owns and controls the wireless infrastructure? James: That was one of the very first things I witnessed when I came here to the Panthers. We had a meeting with all of the carriers that were involved with the existing DAS system. We could tell that there was dissatisfaction among those carriers trying to figure out whether the problem was on their side, or with the DAS neutral host. We felt really powerless being in the middle. We couldn?t figure out exactly what was going on. We couldn?t figure out if we needed to put pressure on this or that carrier or on the neutral-host provider. With that lack of visibility, we just felt like we could never get to the core of the problem, and the problems were never being solved. In the meantime, all our fans were still complaining that they were not getting the coverage they wanted. We decided to move away from a system of managed service, which was essentially what our Wi-Fi and DAS were: we had third parties that owned and managed both the Wi-Fi and the DAS systems. We decided to let those contracts expire and then take over the ownership ourselves. We tried to find the right consultants, such as Beam Wireless, to point us in the right direction, give us the advice we needed so that we would have the expertise on board working with us, while we would maintain ownership of the system, and have full visibility, and take full responsibility for it. Monica: Right now, are Wi-Fi and DAS integrated and you manage both of them? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |111| James: In the case of the DAS system, we contracted with Beam Wireless to help us select a DAS replacement and help us do the construction, integration, optimization, and ongoing maintenance. DAS is pretty complicated. DAS is more complicated than Wi-Fi when it comes to the management and maintenance. In the case of Wi-Fi, we also selected an integrator called AmpThink. They came in and managed the construction and integration, and they are assisting us with our first year of service. Then we?re going to continue with the maintenance ourselves. Although we own both systems, I think the level of support we require from third parties to help us manage them varies between the two. Monica: The decision to take ownership is difficult, because it?s a lot more work on your end. Is it because you think connectivity is something so crucial to you and for your fans that you want to have control? James: It is a scary thing to bring a third-party managed system in house and take full responsibility for that. That was a scary decision, but it was the right decision to make. Because we?ve got a saying here. Our owner, Jerry Richardson, says that the fan is the most valuable member of our team. That?s really important, because what it shows is that his emphasis is on the fan experience. If we?re finding that fans are not getting the connectivity they demand, then we need to fix it. And to fix it, we really felt we just had to take full control. Once we made that decision, started planning, starting building, we realized it was the best decision to make. I think even the carriers agree with us that moving to this new model of DAS ownership was the right choice. Because we are taking that full responsibility, we have high expectations that carriers then can get the benefits of a good system to participate in. Monica: How many carriers participate in the DAS? James: When we built the new DAS system, which was last off-season, in 2015, we maintained the tenants that were there before on the old systems ? Verizon, AT&T and Sprint. We?re currently talking to T-Mobile about also joining the DAS. Monica: In terms of the usage model, the wireless connectivity has become really an integral part of enjoying the experience of a sports event. How has this experience changed through the years? James: New social networking apps come out every day, right? Each one of those leads to challenges. For example, a couple years ago, I had not heard of, or perhaps it did not exist, Periscope ? or the ability to do live video streaming. New apps like that pose real challenges, because with video streaming we?re getting into high bandwidth usage. Then there are also rules about what you can do in a stadium. We?re not supposed to permit a video stream of a game going out live because of usage and broadcast rights. There?s always something new coming out every day. But more importantly, the volume and density have changed. Before, you would say it was a small percentage of our fans that are getting REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |112| on and texting and tweeting and taking selfies. But as our digital natives get older and older, we?re getting more and more of them coming into the football stadiums. Overall it?s really the percentage of users wanting to get online that has changed the most. Kevin: But also one of the big trends we see, and we see this not only in the Panthers stadium but most arenas and venues across the country, is the trend from voice usage to data usage. It used to be making a phone call; now it is sending a text message. That?s how fans communicate during these events. Now it?s Snapchat, Instagram, Facebook. It?s more of the data usage and the multimedia on the phone. You can see that in the DAS statistics. One key thing the Panthers gained by having control and management of their DAS is that they get to see each operator?s statistics after every event. They can see what the true fan experience was per operator after every event. For example, if the lower bowl has a fan experience problem in a certain area, they can focus on that and try to improve that for the fans. They didn?t have that visibility before. Monica: Some of the applications you mentioned are also very heavy on the uplink. Do you see a change in the uplink versus downlink balance? Kevin: That?s something we?re definitely watching. That?s a great question. I haven?t seen a significant change yet. There?s still a big load on the downlink. We?re very curious. So far we?ve had two events this summer. I?m curious to see how the uplink ticks and does the downlink potentially go down? But subscribers are still takers, not givers of content. That?s kind of the expression that they use. Definitely watching it. Monica: What is the balance between cellular and Wi-Fi? James: I was asked this question many times by management here at the Panthers, trying to figure out, ?Hey, if we make our DAS so wonderful, why do we even care about Wi-Fi?? Or, on the other hand, ?Our Wi-Fi is really great. Why do we need DAS? Because I don?t need to get onto the cellular for data.? I do not see how you can avoid having both. In a large venue you?re going to have to have a good DAS system and a good Wi-Fi system. First of all, each system can only go so far. If you?ve got two different systems, that right there is going to help your density problem. Second, you?re going to have expectations from the fans. They may come into a stadium with excellent DAS. They may realize, ?Hey, I don?t want to pay for my cellular data.? Not everybody?s got free cellular data, so they?re going to want that free Wi-Fi. I think you?re going to have the fan demand driving the need for both. You?re going to have the overall density requirements driving the need for both. Monica: Are you looking into using LTE in unlicensed bands? LTE-U, LAA, MulteFire? James: I?m going to start by saying, ?No, I?m going to need the spectrum for Wi-Fi.? But I?m going to let Kevin continue. Kevin: I?ll say, ?Please use it.? It?s funny: because I handle the DAS side, the expectation would probably be that I wouldn?t care that much about Wi-Fi. But I am thrilled to see the new Wi-Fi system going into the stadium, because the biggest help for the DAS is to have that Wi-Fi data offload. It?s extremely important to have both systems in place. We need to offload to Wi-Fi. Wi-Fi needs to offload to us. Not everybody?s going to attach to a Wi-Fi system, and like James said, not everybody?s going to want to pay for data to stay on the cellphone system. They really have to work together. It?s extremely important to have them both. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |113| James: We built the new DAS system first in the off-season of 2015, and the new Wi-Fi system was installed during the off-season of 2016, so we just finished that construction. But as we were doing that construction, I was approached by two of the carriers, wanting to talk about what kind of agreements they can work out with me in order to do the offload. These are the same carriers that are on our excellent DAS system, so you can see they?re very interested in all systems working together, because they recognize the density problem. You have only so much space in Wi-Fi. You have only so much space in DAS. They definitely can complement each other. Monica: When you decided to build your DAS, were there other options, such as small cells, that you considered? Kevin: Macro won?t be able to cover the stadium. There?s too many fans. One or two sectors coming in from an outdoor macro is not going to be able to handle the capacity. That?s not really an option. ?Small cell? is really a loosely used term. A small cell originally had a very minimal capacity. Same thing: that?s not really feasible for a football stadium. The newer term that people use for small cells is really a ?lower-power radio.? That is actually what?s used to feed the DAS. What a lot of people call a small cell now is a 5W radio. But the hardware referred to by original term ?small cell? was used, say, for an office building or something like that. It?s really not feasible for a bowl of a football stadium. Monica: How did you pick the DAS system you have? James: At about the time that I got in contact with Kevin, here, from Beam, we were able to quickly narrow it down to three different DAS types. Then I did some field visits ? went out to other stadiums and took a look at what they had, and we narrowed it down to the final choice. Kevin: We had a long, in depth whiteboard session, and that?s what I encourage any venue to do when it wants another system, is to have this technical whiteboard session. James and I sat down and we drew out every manufacturer and every product line for that manufacturer to discuss what the pluses and minuses would be for the Carolina Panthers. The product we selected might not be the best product line for another football stadium. But then another vendor?s product line might not be best for the Carolina Panthers. One of the reasons we selected the product line that we did was that it comes in what?s called a NEMA-rated form factor. We needed to put remote amplifiers outdoors, where they could be exposed to rain and wind, cold and hot weather. We needed an amplifier that was a little bit more robust as far as power, because all of the carriers were going to share that power. We weren?t going to have separate amplifiers, because of cost and aesthetics. Optimization features were also important. For example, we can attenuate every remote amplifier per band during optimization. That?s extremely important, because a lot of the older product lines didn?t have this capability. It?s really come in handy now. There are also a lot of maintenance advantages that we talked about on the whiteboard. Something very important is the PIM test. Every year, we go through an audit and make sure all the passive infrastructure is still in good shape. For example, take the antennas, the cable and the splitters. How have they been impacted throughout the season? We can actually put this PIM tone through every amplifier in the system very quickly and efficiently ? we can even do it remotely and test all of that passive infrastructure. Monica: Did you choose a passive DAS? Kevin: No, it?s an active DAS. Our DAS has an active amplifier that?s fiber fed and then amplifies through the antennae. Monica: No matter how good your system is, with Wi-Fi and DAS, at some point you?re going to see congestion, because users continue to find new ways to use available capacity. What?s your experience with that? You can?t avoid congestion, but you can manage it. Kevin: Right now, the DAS is fairly new, and we?ve been through one whole season. The DAS is not going to be the bottleneck. It?s basically a very wide interstate or highway that can handle any traffic that the base stations have been sending through it. The bottleneck right now is the operator base station. For example, the DAS as it sits today is designed for 48 sectors of traffic per band, per operator. The most we have running today is 32 REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |114| sectors from one of the operators. Last season the most that we had was 24 sectors from one of the operators. The bottleneck is the sector limitation on how many users their radios can handle. For example, last year, if we take one operator, our failure point was 15 GB on the LTE download in 15 minutes. This year, that same operator has gone from 18 sectors to 24 sectors. Now they?ve exceeded 28 GB in the same 15-minute period without failure. Without changing the DAS from last year to this year, they just increased the base station capacity by increasing the number of sectors. Monica: When you have congestion, from the user perspective, what do the people see? For how long does the network go down? Kevin: We have to talk about congestion in two manners: voice calls and data. We don?t see any voice congestion on the path at all. And I don?t think we have to discuss voice because the trend really has gone from voice to data. For LTE data, typically what happens is that our uplink tanks; that?s the first thing we see in the stats. What we see then is that uplink throughputs, which normally would be several mbps, suddenly go down to 0.1 or 0.05 mbps. The noise rise in that zone is so high that either the customers can no longer communicate with the base stations or their throughput is so slow that the information never gets through. To a customer, what happens is all of a sudden it?s as though it doesn?t work. Their data worked 15 minutes and then all of a sudden, during, say, halftime, which is the busiest time during an event, the device just doesn?t seem to work anymore. What we see then is the payload doesn?t increase, but the attempts increase. What you see is people continuously hammering the system trying to get through. Monica: If you look at it five years from now, you?re going to see a much bigger need for capacity. How are you keeping up? Kevin: It?s a great question. Like I mentioned, today the most that any carrier has is 32 sectors on the DAS. The DAS proper was designed for 48 sectors. When we talk about what it was designed for, what that means is SINR, signal to interference-plus-noise ratio, and channel quality indicator, or CQI. They basically apply to the fan experience. When we look at statistics after an event, if the CQI in a zone is bad, the users in that zone have had a bad experience. What we do is we design a system that?s, say, 48 sectors for a certain SINR level. That?s based on a certain percentage load on the carriers? base station. Once it exceeds that, then we?ll have to come back and modify the DAS. In the bowl, we?ve pretty much hit the limit. The only way to get more sectors in a bowl is adding new antennas, which vendors come out every year with different beam widths, new bands that the FCC licenses. Whether it?s the WCS band on AT&T, the new AWS bands for T-Mobile, Verizon and AT&T, or Sprint?s BRS band, all up in that 2.5-2.6 GHz range, that?s what will happen. Whether it?s RF or noise, it doesn?t matter. We can only put so much of it in one section before it?s not efficient anymore. That?s where additional frequencies come into play. James: The simplest thing we can do to address congestion is to ask the carriers to simply give us more. In other words, if we have 48 zones that are available to them right now in our infrastructure, they need to use all 48 rather than simulcasting their sectors across that. The first thing is the easiest thing, and that is simply tell the carriers, add more capacity. We can take that. This great big highway can take it. As Kevin said, you just need to add more lanes, and that?s really on the carriers. Monica: From your point of view, you?re ready for more capacity as long as the operators come in and make the investment. When they see the unique capacity, they?re likely to make that investment, because it?s clearly to their advantage to provide it. Kevin: We personally discuss that with them. We have everyone?s statistics, and we can compare them. We can really push them in a direction, saying, ?Hey, you have a capacity issue, in this concourse and seating area. Next season or mid- season, you need to double your capacity in this area.? Again, the DAS is prepared for that. James: If we?re doing our jobs right, and the Panthers are, what that really means is we?re going to have little or no congestion. Rather than accepting that congestion is going to happen, we want to have little to no congestion, because we want to meet the fans? demands. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |115| About the Carolina Panthers The Carolina Panthers is a professional American football team that competes in the National Football League (NFL), as a member club of the league?s National Football Conference (NFC) South division. Announced as the NFL?s 29th franchise in 1993, the Panthers began play in 1995. The team is headquartered in Bank of America Stadium in uptown Charlotte, an outdoor 75,412-seat stadium that serves as the team?s home field. The Panthers are one of the few NFL teams to own the stadium they play in. The Carolina Panthers have had two Super Bowl appearances, won two NFC conference championships, six division championships, and seven playoff appearances. About James Hammond James Hammond is the Director of Information Technology for the Carolina Panthers, leading a department of nine staff members who support all technology aspects of the Panthers? operation, as well as wireless, Wi-Fi, and network infrastructure for Bank of America Stadium in Charlotte, NC. As part of an initiative to significantly improve the Panther fans? connected experience, he coordinated the selection, construction, and implementation of a new Distributed Antenna System (DAS) for the stadium, and is currently involved in construction of a new Wi-Fi system consisting of over 1,200 access points. He has also coordinated other major projects, including migration to a new phone system, and implementation of a fiber GPON solution that was part of the renovation of technology in all club suites. In 2013, Mr. Hammond was featured on CNN discussing the advantages and disadvantages of iris scanning and other biometric identification methods. Mr. Hammond previously served as the CIO at Winthrop University and has taught Computer Science at Winthrop University, University of Maryland European Division, the S.C. Governor?s School for Science and Mathematics, and Rutledge College. He has been admitted to candidacy for the Ph.D. in Computer Science at the University of South Carolina. About Kevin Schmonsees With over 17 years of RF design, performance, and optimization experience, Kevin brings a passion for improving the wireless experience in a DAS environment. Having worked for both wireless carriers and integrators, Kevin has extensive hands-on knowledge with 1st-class designs, carrier relationships, installation/implementation, integration, commissioning, and optimization. Kevin's goals with Beam Wireless, Inc. are to bring visibility and control to their clients- allowing them to focus on the overall needs of their customers through a seamless experience. He has a BS Electrical Engineering from NC State University and an MBA from Strayer University. Kevin can be reached at REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |116| Enterprise, anonymous A view on densification from the enterprise A conversation with a Director of Network Architecture and Strategy at a US-based global manufacturing and retail corporation Monica Paolini: This interview is with a Director of Network Architecture and Strategy at a multinational corporation headquartered in the US, that includes multiple business units in the US and abroad, involved in designing, manufacturing, marketing and retail. The interviewee has chosen to remain anonymous and we will refer to him as GM. GM, can you tell us what is your role within the enterprise IT/communications organization? GM: As a Director of Network Architecture and Strategy, I need to make sure the technology trends in the industry are going to match up with the business needs for all the different businesses we have inside of our company. And that covers the network, unified communications, voice, and touches heavily on security. I work very tightly with our internal security group. We need to make sure all those come together. Monica: What wireless infrastructure do you currently have? GM: We are a large Wi-Fi shop. We deployed that a long time ago. We have different, varying densities of Wi-Fi. Cellular has always been a challenge for us, in our buildings, especially as we move to LEED-certified buildings. We opted for a DAS probably 10 years ago. That?s served us pretty well, but we?re seeing limitations as far as density is concerned. We have a very large campus and we keep expanding it. Every time we add a new building, the experience for the rest of the campus goes down. As our populations inside these buildings are getting denser, we?re seeing that that, too, has a degrading effect on the wireless signals. Monica: Are you planning to replace the DAS with more cells, or to extend the DAS in your main campus? GM: I?m looking to move to small cells. I?ve been pushing carriers in that direction. Unfortunately, I haven?t got them on the same page as I am. They have their single-point solution; for each carrier, it?s all different. I?m OK with having different systems for different carriers, but I have a problem with the varying looks of those systems. That sounds weird, but I have a very particular facilities department that goes for a very specific look in each of the offices. I have three different brands of antennas to supply the three different carriers I have. That is a very big challenge for my facilities department. On the technical side, having those three carriers use different systems means all I am getting from them is cellular coverage. If I had one cohesive system, then I might be able to pick up some additional benefits, such as the ability to take calls off of that system and handle the call control ourselves. I have three different systems. That?s never going to happen. Monica: Do you need to have indoor coverage from multiple operators? Wouldn?t one be enough? GM: One of the carriers has about 80% of our traffic. Secondary carrier has about 17% of it. The rest is a couple other small carriers. So, in the US main campus, we need at least two carriers. Monica: Do you have DAS in other locations as well, or only on your main campus? GM: We have DAS in multiple locations. Anywhere there?s been a large problem, with enough people complaining about it, we get a system in there. A lot of these places are smaller, so we don?t do a baseband headend. We end up bringing in the signal from outside, which we have varying luck with. Depends on how bad the cell coverage is outside, and how overloaded the macro cell is. That?s been a mixed bag. Monica: You said you have to work within an environment in which you have multiple operators, each coming with their own REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |117| infrastructure. What kind of alternatives are you considering? GM: What I?d really want is one provider that could give me one system on which I could put multiple carriers. I don?t necessarily want to run the system myself, but I want the benefit of being able to add services as small-cell companies add features. The carrier is not going to offer them at the same rate I want to consume them at. Additionally, if each carrier used different solutions I would not be able to offer the same enterprise features for all employees. Monica: You want to have consistency in your network. On the service part, you want to have all operators being able to support the same services. What is the challenge there for operators? GM: In the area I?m in, Verizon uses Ericsson. AT&T leads with a Nokia solution. Because they?re two disparate solutions, they offer different services. The technology actually may offer some of the same services, but again, carriers only implement the ones they?re comfortable with and they?re willing to support. That means that, even if the technology could support a service, I can?t leverage it, because the carrier decides not to offer it. Monica: In addition to this bifurcation at the service level, you have a similar bifurcation in the access, because you have the different equipment from each operator. GM: Correct, and we?ve actually seen that in our DAS as well. At some of our locations, we have a baseband headend for one carrier, and we?re bringing in the signal from the outside for the other carrier. Even though we have both carriers on our DAS, still one has a better experience than the other. You go to a different building, that might be reversed. Trying to tell VPs about that, they don?t quite get it, and they ask, ?Why can?t we just fix it?? Monica: Do you have a neutral host for your DAS? GM: Yes, we do. Monica: As you move to small cells, is the access going to improve? GM: Each carrier says, ?We will not share with the other carriers.? The reaction to DAS was very similar, in the beginning, to the one I?m seeing in small cells right now. When DAS first came out, every carrier wanted to run their own system and did not want to combine the systems. As DAS matured, we saw more and more carriers allowing other carriers to be on their system, as well as allowing a third party to come in and put in the system and have any carriers join. The carriers are even pitching some money for that. Right now with small cells, we?re in that very first phase, where all carriers want to put in their own system and they don?t want any integration with other systems or vendors. Monica: Why don?t they want to share the small- cell infrastructure? They are used to doing so with DAS. GM: I think it stems from the carrier mentality that ?I do not want to support something I?m not comfortable with.? This is very new for them in the US, and so they?re looking at it and wondering, ?Is this is a solution I?ve vetted? This is what I can prove. I know this would work, but I don?t know if it works when I have all these other carriers on with me. I haven?t seen that.? After small cells get out there and people demand them we?ll hear: ?Oh, we can manage this. We can maintain this.? Monica: One of the key discussion items is about who?s going to pay for this infrastructure. Who do you think should be paying for the equipment and for installation? GM: I feel that, depending on the level of control, I don?t mind owning it. I may not want to run it, I may want to push that to a third party, but I do want to have full control over what features are turned on. Monica: Basically, what you?re saying is that ?I?m willing to pay as long as I have some level of control over what goes on, and what kind of services the operator provides.? You put in some money, and you want to know how that?s being used. What?s the response from operators? GM: With the DAS system, it?s a shared model right now. I pay for some of it, the carriers pay for some of it, and I have no flexibility. I can?t see anything that goes on with that system. Monica: As an enterprise, you may cover the cost of deploying the network but, as you said, you may not want to operate it. Who do you think is best positioned do that? Is it the operators, or is it a third party? REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |118| GM: I say it?s a third party. We have a company right now that comes in, and they?re the ones that work with all carriers. They look at the costs and negotiate deals with carriers. Carriers will only pitch in if it means something to them. They put that case together. This company knows the carriers and the licensed RF space. I don?t have people that are in-depth with that; that?s why I look to a third party for that. Monica: Will the operator or the third party be able to share your indoor wireline infrastructure for backhaul or fronthaul, or do you expect them to build a separate network? GM: This is where I?m going to differ from the director of security. I don?t mind having carriers on my infrastructure. I feel I can isolate them and keep the rest of the network secure. However, I do need to get security?s buy-off on that. That?s going to be one of the challenges we face. I think we can come together. We all see the value of it, and we just work through those issues. I?m not sure how that?s going to play out yet, though. Monica: What about carriers using LTE unlicensed, either LTE-U or LAA, in your campus? GM: That is a very big concern of mine. When we first started looking at small cells, carriers wanted to pair it with Wi-Fi directly. They wanted to run the Wi-Fi for me, or just layer on Wi-Fi on top of it as a guest. Carriers are very good at licensed spectrum. Unlicensed, I don?t think they have as much experience there. Frankly, my enterprise people know that unlicensed spectrum pretty well. I don?t want anybody interfering with the spectrum plan that we put together. Monica: Your workforce is becoming increasingly mobile. Your employees can be anywhere. You could be working from home or a coffee shop off campus, anywhere. How is that changing your wireless strategy? GM: On the Wi-Fi side, which doesn?t come into the licensed carrier spectrum, I?m looking to create the consumer experience. One of the largest complaints of any enterprise customer is ?It works better at home.? What I want to do is give our employees consistency with how they connect to Wi-Fi and LTE whether they are inside or outside our walls. Monica: For you, the challenge is not when your employees go outside the campus, it?s when they are on campus that it becomes the major issue. There is a lot of talk of how operators can offer services that are for the enterprise, and better access. What do you think operators should do differently to support the enterprise better? GM: First one is, solve my problems. My problems are that I need cellular coverage that?s a lot more robust than we have now, a lot more throughput than I have right now, and seamless access inside and outside the walls. When I get to that point, we can talk about what are the things we can leverage on top. If they want to be a partner and come to me with integrations to the rest of my infrastructure, solve my pain points first and then they can definitely have a seat at the table. Monica: The first step is coverage and capacity. Would you say that it?s more coverage, or is it more capacity? GM: Capacity. As we go to the more open-space, the more densified employee footprint inside the buildings, and more mobile, we are getting rid of desk phones everywhere. I don?t think soft phones are going to pan out. People are walking a lot, and are getting rid of laptops. When you?re walking, what?s the only device that really works? It?s your cell phone. Monica: Is latency much of an issue? GM: I tend to look a little bit further out. In working with my application teams, they?re of the same mindset as I am, that they want the experience to be the same outside as inside. They?re building applications for that. You look at the Google Play store, Apple?s store. The apps that are being developed don?t care where they are. They?re built for that user experience. No matter where you are, they?re latency tolerant, and we are designing our user- facing apps the same way. Monica: What about Wi-Fi Calling? That might improve the voice quality, but then you?d have to allow the operators to use your Wi-Fi infrastructure. GM: The issue I have with Wi-Fi Calling is that I would need a user to turn on a feature that will be affecting them even when they are not at work and I cannot guarantee the experience. If they turn on Wi-Fi dialing to achieve a good experience at work but it creates a worse experience for them at home, we are doing a disservice to our employees REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |119| Monica: What do you think are going to be the main changes over the next five years? GM: My main changes are going to be any-device- to-anywhere. Not force people to come through a central area or a central location to get to what they need to. More things in the cloud, more things distributed, and if you need to take off from one of my offices and go to a software as a service, you go directly there. I don?t need to transport you there. Monica: You?re saying multiple devices, but also multiple devices for the same person. It?s not more types but every person would have multiple devices at the same time. GM: It?s more than multiple devices. If you have one device with 10 different apps on it, each one of those apps may be going somewhere different. I don?t want to nail you down because you have one device and one person, to one point. I want you to be able to go everywhere direct. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |120| Glossary 1080p 1080 pixels (or Full HD) 2G Second generation 3G Third generation 3GPP 3rd Generation Partnership Project 4G Fourth generation 4K 4,000 [pixels] 5G Fifth generation AP Access point API Application programming interface ASA Authorized Shared Spectrum ATSC Advanced Television Systems Committee AWS Advanced wireless services BBU Baseband unit BIU Base station interface unit BMS Broadcast/Multicast Service BRS Broadband Radio Service BTS Base transceiver station CA Carrier aggregation Cat 5 Category 5 [cable] Cat 6 Category 6 [cable] CDMA Code division multiple access CoMP Coordinated multipoint CPRI Common public radio interface CQI Channel quality indicator C-RAN Cloud RAN CSI Channel state information CTRL Control D2D Device to device DAS Distributed antenna system DC Data center DMS Device management system DMS DAS management system DSn Digital signal n DWDM Dense wavelength-division multiplexing ECGI E-UTRAN Cell Global Identifier eCSAT Enhanced Carrier Sensing Adaptive Transmission eICIC Enhanced ICIC eMBMS Evolved Multimedia Broadcast Multicast Services EMF Electro-magnetic field EMS Element management system eMTC Enhanced Machine Type Communications E-RAN Enterprise RAN ETSI European Telecommunications Standards Institute E-UTRAN Evolved UTRAN FCC Federal Communications Commission FDD Frequency-division duplex GPON Gigabit passive optical networks GPRS General packet radio service GSM Global System for Mobile Communications HD High definition HetNet Heterogeneous network HIPAA Health Insurance Portability and Accountability Act HROU High [power] ROU ICIC Inter-cell interference coordination ICN Information-Centric Networking ID Identifier iDAS Indoor DAS IEEE Institute of Electrical and Electronics Engineers IMS IP multimedia subsystem IoT Internet of things IP Internet Protocol IPSec Internet Protocol security ISM Industrial, scientific and medical [band] IT Information technology ITU International Telecommunication Union IWPC International Wireless Industry Consortium KPI Key performance indicator L2ROU Low 2 [watt] ROU LAA Licensed-assisted access LAN Large-area network LBT Listen before talk LEED Leadership in Energy and Environmental Design LIPA Local IP access LoRA Long Range [Wide Area Network] LROU Low [power] ROU LTE Long Term Evolution LTE-A LTE Advanced LTE-M LTE for M2M LTE-U LTE Unlicensed LWA LTE Wi-Fi aggregation M2M Machine to machine MAC Media Access Control [layer] MCS Modulation and coding scheme MDU Multiple dwelling units REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |121| MEC Multiple-Access [was: Mobile] Edge Computing MIMO Multiple input, multiple output MME Mobility management entity mmW Millimeter wave MROU Medium [power] ROU MSC Mobile switching center mUE Mobile user equipment NBI North Bound Interface NB-IoT Narrowband IoT NEMA National Electrical Manufacturers Association NFV Network Functions Virtualization OBSAI Open Base Station Architecture Initiative oDAS Outdoor DAS OTDR Optical time domain reflectometer OTN Optical transport network OTT Over the top PBX Private branch exchange PCS Personal communications service PDCP Packet data convergence protocol PDN Plesiochronous digital hierarchy PHY Physical [layer] PIM Passive intermodulation PON Passive optical network POP Point of presence QoE Quality of experience QoS Quality of service RAN Radio access network RAT Radio access technology RET Remote electrical tilt RF Radio frequency ROI Return on investment ROU Remote optical unit RPL Third-party logistics RRC Radio Resource Control RRH Remote radio heads RSRP Reference signal received power SDH Synchronous digital hierarchy SDN Software-defined networking SGSN Serving GPRS support node SGW Serving gateway SINR Signal to interference-plus-noise ratio SIPTO Selected IP Traffic Offload SLA Service-level agreement SON Self-organizing network SONET Synchronous optical networking SSID Service Set Identifier TCO Total cost of ownership TCP Transmission Control Protocol TDD Time division duplex UC Unified communications UDN Ultra-dense network UDP User Datagram Protocol UE User equipment UMTS Universal Mobile Telecommunications System UTRAN Universal Terrestrial Radio Access Network ViLTE Video over LTE VM Virtual machine VoLTE Voice over LTE VoWi-Fi Voice over Wi-Fi vRAN Virtualized RAN WCS Wireless Communication Services WDM Wavelength-division multiplexing WLAN Wireless local area network REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |122| References Anritsu, RF interference hunting techniques: Spot, find, fix, Application Note 11410-00643, Rev. D, 2014. Anritsu, Testing distributed antenna systems: S332E Site Master, MT9083 Access Master, MW82119A/B PIM Master, G0306A/B Connector Inspection Microscope, Application Note 11410-00887, Rev. A, 2015. Anritsu, Understanding IBW solutions: In-building wireless: DAS to small cells, 11410-00885A, 2015. Capretti, C., F. Gringoli, N. Facchi and P. Patras, LTE/Wi-Fi co-existence under scrutiny: An empirical study, Proceedings of the 10th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization, 2016. China Mobile Research Institute, White paper of next generation fronthaul interface, Version 1.0, 2015. CommScope, Wireless in buildings: What building professionals think, 2016. DeGrasse, Martha, Outdoor DAS and small cells, RCR Wireless, 2016. Future Mobile Communication Forum, 5G white paper. I, Chih-Lin, Corbett Rowell, Shuangfeng Han, Zhikun Xu, Gang Li, and Zhengang Pan, Toward green and soft: A 5G perspective, IEEE Communications Magazine, 2014. I, Chih-Lin, Shuangfeng Han, Zhikun Xu, Qi Sun, and Zhengang Pan, 5G: Rethink mobile communications for 2020+, in Philosophical Transactions of the Royal Society A, 2016. International Telecommunication Union, IMT vision ? Framework and overall objectives of the future development of IMT for 2020 and beyond, Recommendation ITU-R M.2083-0, 2015. Ishii, Hiroyuki, Yoshihisa Kishiyama and Hideaki Takahashi, A novel architecture for LTE-B: C-plane/U-plane split and phantom cell concept, Globecom Workshops conference paper, 2012. Kathrein, The role of antenna quality in meeting mobile data demand, 2015. Levi?s Stadium, Super Bowl 50 at Levi?s Stadium sets event record by transferring 10 terabytes of data on gameday, 2016. Lokhandwala, Hatim, Vanlin Sathya and Bheemarjuna Reddy Tamma, Phantom cell realization in LTE and its performance analysis, in Proc. of IEEE ANTS, 2014. Macknofsky, Gary, Understanding the basics of CPRI fronthaul technology, EXFO, 2015. Nakamura, Takehiro, LTE enhancements and future radio access, presented at the 5th Future of Wireless International Conference, 2013. NTT DOCOMO, 5G radio access: Requirements, concept and technologies, 2014. Paolini, Monica, Boosting coverage and capacity with active DAS: The transition from passive DAS to active DAS, Senza Fili, 2015. Paolini, Monica, Charting the path to RAN virtualization: C-RAN, fronthaul and HetNets, Senza Fili, 2015. Paolini, Monica, LTE unlicensed and Wi-Fi: Moving beyond coexistence, Senza Fili, 2015. Paolini, Monica, Real-time backhaul assurance to enhance QoE: The evolution in monitoring LTE networks, Senza Fili, 2016. Paolini, Monica, The economics of small cells and Wi-Fi offload, Senza Fili, 2012. Paolini, Monica, The smart RAN: Trends in the optimization of spectrum and network resource utilization, Senza Fili, 2015. Paolini, Monica, Voice comes to the fore, again: VoLTE and Wi-Fi Calling redefine voice, Senza Fili, 2016. Piecyk, Walter, What does Verizon?s Super Bowl investment tell us about small cells and DAS? BLIG Research blog post, 2016. Qualcomm, Cost-effective enterprise small cell deployment with UltraSON, 2016. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |123| Rysavy Research, Mobile broadband transformation: LTE to 5G, 5G Americas, 2016. Samsung, LTE radio access solution: Expanding possibilities of network experience, 2016. SOLiD, In-building wireless and public-safety imperative, 2015. SOLiD, The need for speed for drivers and wireless fans alike. Sutton, Andy, Small cells and heterogeneous networks, TP Journal, vol. 10, part 2, 2016. Telefonica, in collaboration with Ericsson, Cloud RAN Architecture for 5G. REPORT Massively densified networks ? 2016 Senza Fili Consulting ? |124| About RCR Wireless News Since 1982, RCR Wireless News has been providing wireless and mobile industry news, insights, and analysis to industry and enterprise professionals, decision makers, policy makers, analysts and investors. Our mission is to connect, globally and locally, mobile technology professionals and companies online, in person, in print and now on video. Our dedication to editorial excellence coupled with one of the industry?s most comprehensive industry databases and digital networks leads readers and advertisers to consistently choose RCR Wireless News over other industry publications. About Senza Fili Senza Fili provides advisory support on wireless data technologies and services. At Senza Fili we have in-depth expertise in financial modelling, market forecasts and research, white paper preparation, business plan support, RFP preparation and management, due diligence, and training. Our client base is international and spans the entire value chain: clients include wireline, fixed wireless and mobile operators, enterprises and other vertical players, vendors, system integrators, investors, regulators, and industry associations. We provide a bridge between technologies and services, helping our clients assess established and emerging technologies, leverage these technologies to support new or existing services, and build solid, profitable business models. Independent advice, a strong quantitative orientation, and an international perspective are the hallmarks of our work. For additional information, visit or contact us at or +1 425 657 4991. About the author Monica Paolini, PhD, is the founder and president of Senza Fili. She is an expert in wireless technologies and has helped clients worldwide to understand new technologies and customer requirements, create and assess financial TCO and ROI models, evaluate business plan opportunities, market their services and products, and estimate the market size and revenue opportunity of new and established wireless technologies. She frequently gives presentations at conferences, and writes reports, blog entries and articles on wireless technologies and services, covering end-to-end mobile networks, the operator, enterprise and IoT markets. She has a PhD in cognitive science from the University of California, San Diego (US), an MBA from the University of Oxford (UK), and a BA/MA in philosophy from the University of Bologna (Italy). You can reach her at ? 2016 Senza Fili Consulting, LLC. All rights reserved. The views and statements expressed in this document are those of Senza Fili Consulting LLC, and they should not be inferred to reflect the position of the report sponsors, or other parties participating in the interviews. No selection of this material can be copied, photocopied, duplicated in any form or by any means, or redistributed without express written permission from Senza Fili Consulting. While the report is based upon information that we consider accurate and reliable, Senza Fili Consulting makes no warranty, express or implied, as to the accuracy of the information in this document. Senza Fili Consulting assumes no liability for any damage or loss arising from reliance on this information. Names of companies and products here mentioned may be the trademarks of their respective owners. Cover-page and last-page graphics from brat82/Adobe.