Patent ID: 7515578

Claim:
A method of characterizing at least one of Wi-Fi access points, using the coverage area of the Wi-Fi access point, so that the characterization may be used later to effectively weigh signals transmitted by said Wi-Fi access point when performing a location estimation, the method of characterization comprising: determining the geographic location of the Wi-Fi access points; for each Wi-Fi access point, measuring a plurality of power values for signals transmitted by a corresponding Wi-Fi access point, each power value being measured at position relative to each corresponding Wi-Fi access point; determining a signal coverage area of each Wi-Fi access point based on said measured plurality of power values; dividing the signal coverage area of the Wi-Fi access point into at least two sections, Wherein the coverage area is divided according to at least two radials and at least one distance from the Wi-Fi access point; determining radio propagation characteristics for each section; and assigning a weight to each section based on the coverage areas of the Wi-Fi access points, where sections having relatively small coverage areas are assigned a higher effective weight than sections having relatively large coverage areas, wherein the location estimation will bias its estimate of position to rely on signals detected from the Wi-Fi access points with relatively smaller coverage areas, even if said signals are detected with relatively weaker power than signals detected from Wi-Fi access points with larger coverage areas and relatively higher power.