Bluetooth Low Energy Beacon

A small, low-power wireless transmitter that broadcasts Bluetooth Low Energy (BLE) signals at regular intervals. In accessibility contexts, BLE beacons are widely used for indoor navigation systems for people with visual impairments, as GPS does not work reliably indoors. By placing beacons throughout a building and measuring their signal strength (RSSI) from a smartphone, the user's position can be estimated to within 1-2 metres. Beacons are battery-powered (lasting approximately one year), inexpensive (around each), can be hidden on ceilings or walls, and require no additional hardware beyond a standard smartphone to detect. When combined with fingerprinting techniques and pedestrian dead reckoning, beacon-based systems can provide turn-by-turn indoor navigation guidance.