Passive locating of UMTS handsets

摘要

Passive location determining of a 3G handset is provided. The method may include the following steps: sending a sequence of 3G ‘Pings’ directed at a specified handset over a 3G network; determining the specified handset user identifier and the sewing base station of the specified handset based on reoccurrences of user identifiers responsive of the ping requests, captured from the forward access channel (FACH) of each base station; decoding the FACH of the serving base station responsive to an additional ping, yielding parameters required for receiving uplink dedicated channel (UL DCH); estimating, in each location associated with a base station, a time difference between fastest possible and actual arrival of a signal over the UL DCH sent by the specified handset, wherein the estimating is synchronized to the serving base station; and calculating the location of the specified handset, based on the estimated time differences associated with the locations.

主权项

1. A system, comprising:
a location manager configured to:
initiate a transmission of a request for a user identifier of a communications device, anddetermine, based on information regarding a number of transmissions of the user identifier, a serving base station for the communications device; and a plurality of location measurement units (LMUs) in communication with each other and the location manager, wherein the plurality of LMUs are configured to:
detect one or more transmissions of the user identifier from a base station in proximity to one or more LMUs in the luralit of LMUs, andsend the information regarding the number of the transmissions of the user identifier to the location manager.