Patent ID: 9736639
Date: 2017-08-15
CPC Classifications: G01S,H04B,H04W,Y02D

Claim:
1. Apparatus comprising a second device comprising: a transmitter configured to transmit a first signal to a first device; a receiver configured to receive a second signal that has been transmitted by the first device; a demodulator configured to demodulate a second message from the second signal, the second message including an indication of signal strength of the first signal as measured by the first device; a signal strength measuring module configured to measure signal strength of the received second signal; and a calculator configured to use the indication of the measured signal strength included in the second message and the signal strength of the second signal as measured by the second device to calculate a measure of the distance between the first and second devices, wherein the second device is configured to: measure signal strengths of plural received second signals; demodulate plural second messages from the plural received second signals; and use plural indications of measured signal strength included in the second messages and the plural signal strengths of the second signals as measured by the second device to calculate the measure of the distance between the first and second devices; and wherein the second device is configured to average the plural signal strengths measured by the second device and the plural indications of measured signal strength received from the first device and use the average to calculate the measure of the distance between the first and second devices.