Patent ID: 6339709
Filing Date: 2002-01-15
Classification: G01S

Abstract:
A system for locating a mobile entity in an area including:a) a network of fixed communication beacons for relaying messages, said fixed beacons arranged in predetermined locations, the fixed beacons disposed in a flat structure in which all messages are communicable throughout all fixed beacons; b) a mobile communication beacon adapted to be attached to the entity to be located and for transmitting mobile messages, said mobile messages being coded to uniquely identify the message and to uniquely identify the mobile communication beacon; the beacons being arranged so that operatively, the mobile communication beacon transmits said mobile messages to at least one fixed communication beacon of the network located in its vicinity, said at least one beacon modifying said message by appending a unique beacon identifier and transmitting the modified message to adjacent beacons for transmission throughout the beacon network so that the identity of the at least one fixed communication beacon which first modified the message is stored at each fixed beacon throughout the network.