HOW IT WORKS
Measure the angle, not the strength.
RSSI guesses distance from how loud a signal is — and a washroom wall, a metal rack or a passing forklift changes loudness without moving anything. Angle of Arrival measures the physical direction the signal comes from instead, which the environment cannot fake.
Each anchor carries an antenna array. As a Bluetooth 5.1 tag transmits, the anchor reads the phase difference across its antennas and recovers the pitch and heading angle of the incoming signal. From a single anchor and the known mounting height, that resolves to a 2D position on the floor; where two or more anchors see the same tag, the intersection of their angles gives a full 3D coordinate.
A fusion engine sits above the anchors. It cross-validates angles from every anchor that can see a tag, filters the reflections and BLE signal-bleed that defeat simpler systems, and outputs one stable position rather than a cloud of competing estimates. Adding anchors extends coverage across corridors, rooms and yards without changing the method — the same maths, more eyes.