Monday, September 26, 2016

Bluetooth Low Energy - Guiding our Way in the Future

Bluetooth Low Energy (BLE) refers to a low power broadcast mode commonly referred to as a beacon (Bluetooth beacon, iBeacon).  BLE broadcast is a limited protocol intended to be received only by proximate user devices (less than 100 meters).  The beacon presents "effectively" a unique serial number.  An application can lookup the location of a beacon by its serial number.  An application can use the BLE beacon-derived position to trigger appropriate actions.

The typical use case would have a beacon at the door of a retailer trigger a notification on a smartphone, when entering the store, offering a greeting and compelling promotions. BLE has significant potential to enhance a richer interaction with a facility by managing the movement of persons through facilities and locales and especially as an aid to those needing assistance.  

Examples include aiding visually-impaired persons navigating unfamiliar surroundings in the home, on the street, in the office, and while traveling on an airplane.  Those with other impairments are equally benefitting.  Further aspects are related to tracking persons and assets.

BLE devices are a simple circuit and power supply that can be manufactured into a small form factor roughly the size of the small coin-battery powering it.  These device batteries can operate for years depending on the size and broadcast transmit power and  intervals.  BLE beacons can cost less than $1 to produce.

Smartphones support the reception of BLE beacons.  For the purpose of aiding an individual, the presumption will be that Bluetooth is turned on and that the appropriate application is running in the foreground.

Anyone can install BLE beacons anywhere, within the limits of propriety.  It is possible to receive BLE beacons from any provider - the point of the technology is everyone can receive them.  Therefore it is possible to incorporate all BLE beacons into an application, with the caveat that beacons not under control may be moved or not available at any time.  In many cases, multiple beacons are received at a given location allowing for more comprehensive detection of rogue or other types of beacon issues.

Smartphones can utilize cellular, Wi-Fi, GPS, and Bluetooth to determine locations.  GPS offers autonomous positioning.  Cellular, Wi-Fi, and Bluetooth offer relative positioning reliant on a data base to calculate actual position.

Smartphones can host extensive data locally in memory and may use connectivity to access a central repository of information that is unlimited.  Applications can move information from a central repository to limited local memory in the context of what may be needed - in essence the local memory can be kept up-to-date in detail within a limited region, even if subsequently off-line.

Smartphones can interact with their user visually through their display and indicators, through the speaker using ringing or other aural indications, and physically through a sequence of vibrations.  Smartphones can interact with peripherals that can offer further enhancements, for example, stereo ear pieces, vibrating shoe inserts, or a smart cane.

Smartphone applications can piece together the BLE reception, connecting to central server data bases, drive integrated and peripheral interfaces, and the local computing facility to tie sensors to outputs.

Consider the use of BLE positioning in a home.  A set of beacons is installed throughout the home allowing for discrimination necessary to locate entry/exit, bathroom, bedroom, kitchen, dining, living rooms.  A floorpan layout and the location of each beacon entered is into an application.  The application can use BLE to locate the receiver and offer guidance to any destination.  

Consider the use of BLE positioning in a neighborhood.  A set of beacons are deployed in a matrix along each roadway, intersection, crosswalk, and point-of-interest/business. A street map and the location of each beacon are entered into an application.  The application can use BLE to locate the receiver and offer guidance to any destination.

BLE beacons can be driven actively to communicate state information of the beacon.  BLE beacons can be powered and part of an active computer system.  For example, a cross-walk beacon can annotate its broadcast to indicate whether to cross or not (Walk --Flashing Don't Walk --Don't Walk).

Consider the the use of BLE positioning in the office.  The requirements are similar to the home, except the extent is much greater.  The home might be a condominium or apartment complex, so the lines blur.  An inside-home deployment would be something any individual should be capable of completing, whereas covering common areas or commercial areas would require more participants.

Consider the use of BLE positioning as an airline passenger.  The airport and the airplane are the two venues to be encountered.  

A set of beacons would be deployed throughout the airport.  These beacons would locate the pathways from check-in, security, to the gates, and upon arrival to the exits, baggage claim, and transportation.  Beacons would locate points-of-interest (bathrooms, organizations, businesses).  The beacons may actively indicate wait times, or the application may use central facilities to note congestion, best options, and estimates for traversing.

A set of beacons would be deployed in the airplane.  These beacons would locate the seats, the exits, and the bathrooms.  An application would be able to guide a person along the aisle way.  An active set of bluetooth access points could present interactive features with the smartphone to complement cabin announcements.

Tracking applications relate to reporting the presence of a beacon to a central data base that can associate that beacon to a physical location or to a physical asset.  Beacons can be worn or attached to physical assets without undue burden.  Assets may include any "thing". 

A smartphone can be tracked by reporting it reporting its BLE position.  A beacon is tracked by a smartphone reporting the reception of a beacon.  

For example, an airline mechanic may wear a BLE beacon integrated within their "badge".   Every smartphone that receives that beacon broadcast can report it to a central data base.   The mechanic walking by a passenger with an application listening for beacons would create a report that could be correlated to the passenger position, and therefore approximate where the mechanic was.  

A BLE receiver could be installed at the doorway of an airplane, sense whenever someone enters or exits the airplane, and report their arrival or departure.  

Passenger smartphones can effectively become full-time sleuths listening for any long-lost asset, even if hidden behind a closed door.

BLE receivers can be used to track any asset: e.g. checked bags, catering, service vehicles, test equipment, service equipment.

An airline can use BLE position to locate passengers that need to proceed to their gate by knowing how long it takes to complete the walk.   The airline could use the application to notify the passenger directly, or the airline could dispatch persons to assist the passenger in reaching the departing gate.

There is no end to what we can do with BLE!  It all stems from low-cost BLE beacons, pervasive smartphones, and the cloud.

<NOTE: this is a working paper that I am continually revising>

Peter Lemme
peter @

Follow me on twitter: @Satcom_Guru

Copyright 2016   All Rights Reserved




    Bluetooth beacon transmitters come in a variety of form factors, including small coin cell devices, USB sticks, and generic Bluetooth 4.0 capable USB dongles. Bluetooth low energy beacon