to implement 'handset based' location by global positioning system (gps) or similar technology in each phone, or 'network based' location by means of triangulation between cell towers. the order set technical and accuracy requirements: carriers using 'handset based' technology must report handset location within 50 meters for 67% of calls, and within 150 meters for 90% of calls; carriers using 'network based' technology must report location within 100 meters for 67% of calls and 300 meters for 90% of calls. the order also laid out milestones for implementing wireless location services. the first phase i wireless 911 call was in september 1997 in allentown, pennsylvania. many carriers requested waivers of the milestones, and the fcc granted many of them. by mid-2005, implementation of phase ii was generally underway, limited by the complexity of coordination required from wireless and wireline carriers, psaps, and other affected government agencies; and by the limited funding available to local agencies which needed to convert psap equipment to display location data (usually on computerized maps). in july 2011, the fcc announced a proposed rule requiring that after an eight-year implementation period, at some yet-to-be-determined date in 2019, wireless carriers will be required to meet more stringent location accuracy requirements. if enacted, this rule would require both "handset based" and "network based" location techniques to meet the same accuracy standard, regardless of the underlying technology used. the rule is likely to have no effect as all major carriers will have already achieved over 85% gps chipset penetration, and are thus able to meet the standard regardless of their 'network based' location capabilities. in canada in 2009, the canadian radio-television and telecommunications commission (crtc) required implementation of phase ii stage 1 for wireless carrier by 1 february 2010, in areas that provide landline e911. many canadians now have access to phase ii service. public safety answering point (psap) the final destination of an e911 call (where the 911 operator sits) is a public safety answering point (psap). there may be multiple psaps within the same exchange or one psap may cover multiple exchanges. the territories (emergency service zone) covered by a single psap is based on the dispatch and response arrangements for the fire, police, and medical services for a particular area. all primary psaps have a regional emergency service number (esn), a number identifying the psap. the caller location information (cli) provided is normally integrated into emergency dispatch center's computer-assisted dispatch (cad) system. early cad systems provided text display of the caller's address, call history and available emergency response resources. in 1994, working in cooperation with the emergency response agencies of covington, ky, 911 mapping systems, inc. founded in 1992 by robert graham thomas jr., implemented the first real-time on-screen e911 street map display to highlight the caller's position, nearest available emergency responders and other relevant information such as fire hydrants, hazardous materials and/or other data maintained by the city. shortly thereafter, integrated mapping became a standard and integral part of all cad systems and continues to evolve alongside 911 response technology. for wireline e911, the location is an address. for wireless e911, the location is a coordinate. not all psaps have the wireless and wireline systems integrated. interconnection details each telephone company (local exchange carrier, or lec) has at least two redundant ds0-level (that is, 64 kbit/s, or voice quality) trunks connecting each host office telephone switch to each call center. these trunks are either directly connected to the call center or they are connected to a telephone company central switch that intelligently distributes calls to the psaps. these special switches are often known as 911 selective routers. their use is becoming increasingly more common as it simplifies the interconnection between newer isup/ss7-based host office switches and the many older psap systems. if the psap receives calls from the telephone company on older analog trunks, they are usually pulse driven circuits. these circuits are similar to traditional telephone lines, but are formatted to pass the calling party's number (automatic number identification, ani). for historical reasons, the psap will refer to these as cama circuits even though centralized automatic message accounting (cama) is actually a reference to the call log. if the psap receives calls on older-style digital trunks, they are specially formatted multi-frequency (mf) trunks that pass the calling party's number (ani) only. some of the upgraded psaps can receive calls on isup trunks controlled by the ss7 protocol. in that case, the calling party's number (ani) is already present in the ss7 setup message. the charge number parameter contains the ani. voip enhanced 911 voip enhanced 911 pertains to communications originating from various commercial services provided by companies that send telephone calls across the commercial internet using specialized devices and software applications. as voice over internet protocol (voip) technology matured, service providers began to interconnect voip with the public telephone network and marketed the voip service as a cheap replacement phone service. however, e911 regulations and legal penalties have severely hampered the more widespread adoption of voip: voip is much more flexible than land line phone service and there is no easy way to verify the physical location of a caller on a nomadic voip network at any given time (especially in the case of wireless networks), and so many providers offered services which specifically excluded 911 service so as to avoid the severe e-911 non-compliance penalties. voip services tried to improvise, such as routing 911 calls to the administrative phone number of the public safety answering point, adding on software to track phone locations, etc. the location information server is a service that is provided by an access network provider to provide location information to users of the network. to do this, it uses knowledge of network topology and a range of location determination techniques to locate devices that are attached to the network. the precise methods that are used to determine location are dependent on the type of access network and the information that can be obtained from the device. initially, the u.s. federal communications commission (fcc) took a hands-off approach to voip in order to let the service mature, and also to facilitate competition in the telephony market. in time, this problem reached the headlines of newspapers as individuals were unable to place emergency calls with their voip phones. in march 2005, texas attorney general greg abbott filed a lawsuit against vonage for deceptive marketing practices by not making it clear that voip users had to actually sign up for e911 service. when fcc chair kevin martin replaced fcc chair michael powell, he immediately changed fcc's hands-off policy and moved to impose 911 obligations on voip service providers. in 2005, chair martin moved fcc to require "interconnected voip services" to begin to provide 911 service and provide notice to their consumers concerning the 911 limitations. the fcc announced that customers must respond to the e911 voip warning and those who do not have their service cut off on august 30, 2005. the fcc extended the deadline to september 28, 2005. the e911 hookup may be directly with the wireline e911 network, indirectly through a third party such as a competitive local exchange carrier (clec), or by any other technical means. the fcc explained that they felt compelled to issue this mandate because of the public safety concerns. vonage co-founder jeff pulver opined that this was an attempt by fcc chair martin to hinder telephony competition to at&t. the 911 obligations were imposed only on "interconnected voip." the fcc defined "interconnected voip" as voip over broadband that interconnects with the public switch telephone network. voip that is not interconnected, such as two individuals talking to each other over the internet while playing computer games, does not fall under the obligation. there are, however, complicated technological problems with implementing e911 with voip, which providers are attempting to solve. voip phones are on the internet and nomadic; the geolocation of the individual placing the 911 call can be very difficult to determine. service providers are attempting to phase in solutions through the i1, i2, and i3 phases. during i1, the 911 call was routed to the 911 administrative telephone lines without location information. during i2, voip services would participate in the public telephone networks location database for the location that is identified with that telephone number. during the i3 solution, voip service providers would have a true ip interconnection with public safety answering points and would be able to provide even more valuable information than the legacy 911 system. where voip phones are mobile, geolocation has additional problems; voip service providers are seeking access to mobile phone location databases. these solutions are being developed through the cooperation of the voice on the network coalition and the national emergency number association. vonage has encouraged its customers to register the locations from which their 911 calls could be dialed with the local public safety answering point. the fcc had continued to add more requirements and mandate a more sophisticated 911 function. voip services have noted an obstacle to full 911 interconnection; in order to interconnect with the public safety answering point, the voip service providers must interconnect with the 911 telephone trunk, which is owned and controlled by their competitors, the traditional fixed-line telephone carriers. this resulted in the new and emerging technologies 911 improvement act of 2008 which granted interconnection rights to interconnected voip services. in response to the e911 challenges inherent to ip phone systems, specialized technology has been developed to locate callers in the case of emergency. some of these new technologies allow the caller to be located down to the specific office on a particular floor of a building. these solutions support a wide range of organizations with ip telephony networks. the solutions are available for service providers offering hosted ip-pbx and residential voip services. this increasingly important segment in ip phone technology includes e911 call routing services and automated phone tracking appliances. many of these solutions have been established according to fcc, crtc, and nena i2 standards, in order to help enterprises and service providers reduce liability concerns and meet e911 regulations. in recent years there have been numerous important developments in e911 solutions for ip phone technology. the more noteworthy of these developments include: on-site appliances that automate and simplify e911 management for enterprise ip-pbx systems, reducing administration, ensuring that ip phone locations are always up to date, thus helping enterprises meet their e911 obligations; ip phone tracking that automatically assigns locations to ip hard phones, soft phones and wireless phones as they move on the corporate network using layer 2, layer 3, or wireless lan discovery. support for remote employees, allowing off-campus users and teleworkers to update their locations in real time directly from their ip phones; support for phone mobility, to ensure accurate e911 services for employees that move ip phones between locations, share line appearances between multiple devices, and log into ip phones on the fly; security desk routing and notification functionalities that deliver 911 calls and custom email alerts to on-site security personnel, notifying them of the emergency and providing them with the caller’s precise location information; advanced e911 call management and reporting features, such as misdial protection and call recording, to improve solution performance and administration. voip & 911 issues are also relevant to telecom relay services utilized by individuals with disabilities. multi-line telephone system multi-line telephone system (mlts) pertains to the location of callers dialing 911 from within the private telecommunications networks used by large organizations. a multi-line telephone system (mlts), often referred to as a private branch exchange, is a telecommunications switching system used by large organizations to process calls between employees within the organization and with parties external to the organization. an mlts may serve a single building, segments of multi-tenant buildings, a group of buildings on a campus or even a number of buildings separated by geography. new communications technologies are making it possible for single mlts systems to serve locations at far distant places that may span multiple governmental jurisdictions even distant countries. the challenge of enhanced 911 for the mlts is that information about the location of callers is only available to the extent that the private organization discloses the information. for the organization the challenges of collecting and reporting the information can be significant. today’s highly mobile