BLE devices installed in indoor environments are Bluetooth 4.0 beacons that can be placed very easily by adhesive to any surface. The battery is easily replaceable without removing the beacon from the wall, the battery can last about a year.
Bluetooth Low Energy beacons send advertising packets using channel 37,38 and 39 of the 2.4 GHZ band. This advertising packets are sniffed and its power measured in order to estimate the position.
The positioning software on smartphones get the necessary metrics from the signal emitted by Smart Beacons installed in the environment and calculates the position in real time with technology based on radio-map filtering and probabilistic techniques.
