Patent ID: 6154139
Filing Date: 2000-11-28
Classification: G08B

Abstract:
A method for locating subjects within a tracking environment, the method comprising the steps of:for each subject, providing a TAG capable of transmitting a substantially line-of-sight signal including a unique TAG ID substantially simultaneously with a substantially non-line-of-sight signal also including the unique TAG ID;providing an array of receivers distributed within the tracking environment, wherein the array of receivers includes an extended area receiver for receiving a plurality of substantially non-line-of-sight signals and a plurality of limited area receivers, each of the limited area receivers receiving substantially line-of-sight signals;generating an extended area detection packet including the unique TAG ID in response to each received non-line-of-sight signal;generating a limited area detection packet including the unique TAG ID in response to each received line-of-sight signal; anddetermining the location of each TAG and its associated subject based on the identity of the extended area and limited area receivers for the TAG as represented by its extended area and limited area detection packets.