Patent ID: 6421009
Filing Date: 2002-07-16
Classification: H01Q

Abstract:
A local area direct law enforcement emergency notification system for determining the position of a mobile station in a cellular communications network, comprising:at least three independent locator units installed in each cell and fixedly positioned for tracking and measuring communications between a base station and said mobile station initiating an emergency communication, each said locator unit comprising; omni directional receiving means for monitoring control channels of said base station for detecting and receiving mobile station identifying information including an assigned voice channel associated with said particular mobile station initiating said emergency communication; storage means for storing said identifying information associated with said emergency communication; controller means for tuning said omni directional receiving means to the assigned voice channel associated with said emergency communication for receiving voice and control channels data between said base station and said mobile station; omni directional transmission means operable in a first mode responsive to said omni directional receiving means and said controller means for initiating a second, direct communication to at least one independent portable monitor unit based on said stored identifying information, said second communication further including data indicative of the signal strength of said mobile station relative to said particular locator unit; wherein at least one said independent portable monitor unit is responsive to said plurality of independent locator units for receiving said second communication from each said locator unit and determining and tracking the position of said mobile station based on said received signal strengths and the known position of said fixed independent locator units.