Patent ID: 6344794
Filing Date: 2002-02-05
Classification: G06K

Abstract:
A personnel and asset tracking system for locating and tracking objects throughout an awareness area, said personnel and asset tracking system comprising:a communication network; a central server connected to said communication network maintaining an awareness area database; a plurality of tags, each tag being associated with an object to be tracked and having a transmitter which periodically transmits a tag transmission, said tag transmission including a unique object identifier; an independent monitoring system monitoring a first sub-awareness area covering a portion of said awareness area, an assigned subset of said tags being assigned to said independent monitoring system, said independent monitoring system comprising: a master station connected to said communication network, said master station maintaining a sub-awareness area database containing a location for each of said assigned subset of said tags, an intermediate location processor connected to said master station, a plurality of independent receiver nodes connected to said intermediate location processor and configured to receive tag transmissions from a portion of said first sub-awareness area; wherein receiver location messages are generated by said plurality of independent receiver nodes in response to a received tag transmission from a proximate one of said plurality of tags and are transmitted to said intermediate location processor, said intermediate location processor processes said receiver location messages and transmits intermediate location messages to said master station, said master station processes said intermediate location messages and transmits master location messages to said central server over said communication network, processing by said master station including updating said sub-awareness area database with the location of said proximate one of said plurality of tags; a second monitoring system monitoring a second sub-awareness area covering a portion of said awareness area, said second monitoring system generating downstream location messages in response to tag transmissions received in said second sub-awareness area and transmitting said downstream location messages to said central server over said communication network; said central server updating said awareness area database with said master and downstream location messages received, responding to queries by said master station, and determining whether said downstream location message is for one of said assigned subset of said plurality of tags and, if so, generating a network location message identifying said one of said assigned subset of said plurality of tags and its location and transmitting said network location message to said independent monitoring over said communication network for updating said sub-awareness area database.