Bluetooth direction finding is the major feature of the Bluetooth 5.1 Core Specification. It is designed to enhance location services where previously only signal strength based technology has been used with Received Signal Strength Indication (RSSI).
Bluetooth direction finding will offer new and improved use case for Real Time Location Systems (RTLS) for asset tracking in a wide range of scenarios from logistics and warehousing to value asset security in hospitals and factories. It also brings added user experiences in proximity-based scenarios for consumer awareness and contextual information.
Bluetooth direction finding can be used to detect location in either 2D or 3D dependent on the complexity of its implementation.
Angle of Arrival (AoA) and Angle of Departure (AoD)
Bluetooth direction finding is based around the two key concepts of Angle of Arrival (AoA) and Angle of Departure (AoD). This makes use of the angular phase-shifts that occur between antennas as they receive (AoA) or transmit (AoD) RF signals.
With the use of antenna arrays at either side of the communication link phase shift data can be determined and from this, location can be calculated.