Patent ID: 7733836

Claim:
A method of estimating location of a beaconing device within a building, comprising: concurrently transmitting from the beaconing device at least first and second signals respectively indicating at least first and second transmit power levels thereof; receiving the at least first and second signals by a plurality of anchor devices at different known locations; estimating first distances between the beaconing device and each anchor device as a function of signal power levels of the first signal received by each anchor device, and second distances between the beaconing device and each anchor device as a function of signal power levels of the second signal received by each anchor devices; calculating an estimated location of the beaconing device as a function of the estimated first distances and second distances; and when calculating the estimated location of the beaconing device, assigning a weighting factor to each estimated distance as a function of the transmit power level transmitted from the beaconing device and the corresponding signal power level received by each anchor device, wherein the weighting factor to each estimated distance using a lower power level weights over the weighting factor using a higher power level.