In an RF environment serviced by 802.11, Bluetooth(.TM.), or other network
transmitters, or combinations, location-estimation methods and systems
can advantageously use redundancy to refine an estimated location of an
RF receiver. In one embodiment, a method for finding a receiver's
location includes receiving signals from fixed transmitters, calculating
preliminary location estimates, and combining the estimates using
predetermined reference information on the RF environment. The reference
information preferably includes minimum mean-squared error optimizing
coefficients.