670
edits
Changes
→Solution description
==Solution description==
==Solution description==
First, BLE beacons are set up in an inside space, their position will remain fixed and they will serve as a known location reference. These beacons periodically broadcast a signal which is unique for each beacon containing the beacon’s ID. All FM devices can detect this broadcasted signal, therefore, many FM devices can utilise the set up beacons for positioning simultaneously. Once a FM device configured for the solution receives a signal from a beacon, the relationship between the strength of this received signal (RSSI-Received signal strength Indicator) and transmitted signal strength (which is a constant for each beacon), will be proportional to the distance between them, as radio waves propagate according to the inverse square law. With several beacons detected by the FM device and having calculated the distance to each of them, the position of the configured FM device can be approximated by a positioning algorithm, such as trilateration. These calculations are performed on the server side.
First, BLE beacons are set up in an inside space, their position will remain fixed and they will serve as a known location reference. These beacons periodically broadcast a signal which is unique for each beacon containing the beacon’s ID. All FM devices can detect this broadcasted signal, therefore, many FM devices can utilise the set up beacons for positioning simultaneously. Once a FM device configured for the solution receives a signal from a beacon, the relationship between the strength of this received signal (RSSI-Received signal strength Indicator) and transmitted signal strength (which is a constant for each beacon), will be proportional to the distance between them, as radio waves propagate according to the inverse square law. An example of distance, in meters, to the beacon can be calculated by:
<math>Distance = 10^{\frac{Measured Power-RSSI}{10N}}</math>
Where,
Measured Power is the RSSI value one meter away from the beacon if it is using iBeacon protocol, or 0 meters away if it is using Eddystone protocol.
N is a constant for the environmental factor. It has a value between 2-4 and should be determined experimentally based on the facility.
With several beacons detected by the FM device and having calculated the distance to each of them, the position of the configured FM device can be approximated by a positioning algorithm, such as trilateration. These calculations are performed on the server side.
[[File:452697 eye beacon warehouse 1.3.png | Principle of operation]]
[[File:452697 eye beacon warehouse 1.3.png | Principle of operation]]
