Patent ID: 7257373

Claim:
A method of determining, using one or more signal strength readers, the proximity of wireless devices relative to a reference point, comprising the steps of: accessing signal strength calibration data associated with said reference point; measuring the transmission strength of wireless transmissions from all wireless devices within range of said one or more signal strength readers; comparing the signal strength calibration data with the measured transmission strength of the wireless transmissions of each of said wireless devices within range of said one or more signal strength readers; identifying the proximity of said transmitted devices relative to said reference point based on said comparison; measuring, relative to said one or more signal strength readers, the strength of a calibration signal generated at said reference point; and storing said measured calibration signal strength value as said signal strength calibration data; wherein said proximity identifying step comprises the steps of: calculating an adjacency metric for each of said wireless devices within transmission range of said one or more signal strength readers; and identifying the wireless device having the lowest adjacency metric as being closest to said reference point.