Patent ID: 7738881

Claim:
A system, comprising: a signal component that receives a plurality of ambient signals from a plurality of commercial FM radio station transmitters that each provide at least one ambient signal used by a device to determine at least one approximate location of the device; a ranking component that computes a rank vector of at least the subset of the ambient signals based at least in part on relative signal strengths between the subset of ambient signals and maps the rank vector to an integer; an analysis component that infers the at least one approximate location of the device based, in part, on comparing the integer to a plurality of hash codes related to one or more disparate permutations of the rank vector; and a training component for training the analysis component based at least in part on the one or more hash codes corresponding to the one or more permutations of the rank vector and a related location, the one or more rank vectors are computed based at least in part on relative signal strength of the ambient radio signals at the related location; wherein each ambient signal is associated with a commercial FM radio station.