Patent attributes
A wireless node location mechanism that employs a differential signal strength metric to reduce the errors caused by variations in wireless node transmit power, errors in signal strength detection, and/or direction-dependent path loss. As opposed to using the absolute signal strength or power of an RF signal transmitted by a wireless node, implementations of the location mechanism compare the differences between signal strength values detected at various pairs of radio receivers to corresponding differences characterized in a model of the RF environment. One implementation searches for the locations in the model between each pair of radio receivers where their signal strength is different by an observed amount.