Methods, apparatuses, and systems directed to a wireless node location
mechanism that uses a signal strength weighting metric to improve the
accuracy of estimating the location of a wireless node based on signals
detected among a plurality of radio transceivers. In certain
implementations, the wireless node location mechanism further
incorporates 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 present invention 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 of the invention searches for the
locations in the model between each pair of radio receivers where their
signal strength is different by an observed amount.