Patent ID: 7420510

Claim:
A system for tracking persons and other assets in a structure, comprising: a multi-function tracking tag comprising an RF beacon for transmitting an RF beacon signal and a dead reckoning module, said RF beacon signal including data from said dead reckoning module; a plurality of RF transceivers of known location forming a wireless array for receiving said RF beacon signal from said multi-function tracking tag and thereafter re-transmitting said RF beacon signal; and a computer associated with said plurality of RF transceivers, said computer being programmed to determine a location of said multi-function tracking tag using an algorithm wherein said algorithm utilizes signal strength of said RF beacon signal and said data from said dead reckoning module to calculate said location of said multi-function tracking tag wherein said algorithm minimizes a squared error between a position estimate based on said signal strength of said RF beacon signal and a position estimate based on said data from said dead reckoning module.