Patent ID: 7873367

Claim:
A method in a locationing module of an Radio Frequency (RF) switch for locating a first wireless device having a first type within a wireless network comprising a plurality of second wireless devices having a second type, comprising the steps of: identifying an overlap area corresponding to the intersection of RF ranges for the plurality second wireless devices; computing a set of signal strength values, each associated with a measure of RF signal strength received by the plurality of second wireless devices from the first wireless device; evaluating a decision metric for a plurality of locations within the overlap area based on the set of signal strength values, wherein the decision metric is a minimum mean square error (MMSE) defined by MMSE = ∑ n = 1 N ⁢ ⁢ K n ⁡ ( RSSI MU , n - RSSI predicted ⁢ _ ⁢ AP , n ) 2 where N is the number of second wireless devices seen by the first wireless device, where N>1, RSSI MU,n is the live or reported receiver signal strength indicator (RSSI) of the first wireless device to the nth second wireless device, RSSI predicted — AP,n is the predicted RSSI for the first wireless device from the perspective of the nth second wireless device, and K(n) is a weighting function used to remove duplicate RSSI values associated with the same second wireless device from the set of signal strength values; and determining the location of the first wireless device by selecting, from the plurality of locations, a location having the optimum value of the decision metric within the overlap area.