摘要 |
In a communication system, a location server is provided for receiving a location request. A plurality of base stations whose locations are predetermined are connected to the location server. In response to the location request, the system determines a round-trip propagation delay time of packets asynchronously transmitted over a wireless channel between each of the base stations and a target mobile station, calculates the distances from the round-trip propagation delay times, and estimates the location of the mobile station from an intersection of a plurality of circles whose radii are equal to the distances and whose centers respectively coincide with the locations of the base stations. The location server returns a location report to the requesting source for indicating the location of the mobile station. |