Method and apparatus for determining whether a wireless station is operating within a prescribed geographic region

摘要

A method and apparatus determine whether a wireless station (102) is operating within a prescribed geographic location (104). During an initialization process, the wireless telephone (102) measures propagation delays of pilot signals from nearby base stations (110,120,130,140) and stores the propagation delays in a non-volatile memory of the wireless station. Thereafter, during a check process, the wireless station measures propagation delays of pilot signals from nearby base stations and compares them with the stored propagation delays stored in memory. If the difference between the two sets of propagation delays are within a predetermined tolerance, then a determination is made that the wireless station is operating within the prescribed geographic location. Multiple sets of propagation delays may be stored in memory such that a determination can be made as to whether the mobile station is operating within any one of a number of prescribed geographic locations.