Patent ID: 7263375

Claim:
A system comprising: a transmitter unit at a known, fixed location within a building, transmitting a wireless signal unique to that location; a portable receiver or receiver/reader/memory located with said building, for receiving said wireless signal transmissions from said transmitter unit, a processor co-located with said portable receiver, for storing information relating to the physical environment around at least said known location and information identifying said signal unique to said location, and for processing said signal unique to said location in conjunction with said information relating to the physical environment, for producing a human-sensible map of said environment around at least said known location in which communications between said receiver and processor contain not only received signal identities, but also received signal strengths in a normalized, relative measurement; and wherein said signal strengths are processed to determine which signal of numerous signals is strongest and presumed to be within closest proximity, which is second, and so on until all sufficiently-received signals are ranked.