After reading through papers and literature about BLE and iBeacons I am a bit confused as to whether the Meas. Power/TX Power in the advertising packets is being used to determine the proximity to an iBeacon? Or does a mobile device rely solely on the received RSSI?
i.e. is the RSSI compared to the value that is within the advertising packet to (help) determine the proximity to an iBeacon?
The measured power field tells the mobile device what the RSSI should be if the beacon is exactly one meter away. If the measured power is equal to the RSSI, the estimated distance will be 1.0 meters. If the RSSI is stronger (a smaller magnitude number) the estimated distance will be < 1.0 meters. If it is weaker, it will be > 1.0 meters.
There is a formula that can estimate the distance based on these two numbers: Understanding ibeacon distancing
