Patent ID: 7983622

Claim:
In a wireless communication system that includes wireless service sites and that provides service to access terminals, a method of confirming that a wireless service site is valid choice for providing service to an access terminal, the method comprising: receiving a particular signal at the access terminal from the wireless service site; receiving a reference signal at the access terminal from a serving wireless service site; determining a reference phase based on the reference signal; determining an observed phase of the particular signal, the observed phase being a phase of the particular signal measured relative to the reference phase; determining an expected phase of the particular signal based on a postulated identity of the wireless service site; determining a phase shift of the particular signal as a difference between the observed phase of the particular signal and the expected phase of the particular signal; converting the determined phase shift into a differential distance; and confirming the wireless service site to be a valid choice for providing service to the access terminal upon a determination that the differential distance does not exceed a threshold distance.