SYSTEM FRAME NUMBER (SFN) EVALUATOR

摘要

An access terminal (102) reacquires a system frame number (SFN) when a difference between a continuous counter elapsed time (220) and a calculated elapsed time (222) exceeds a threshold. The continuous counter elapsed time (220) is generated by a continuous counter (122) remaining active during a sleep state of the access terminal (102) and the calculated elapsed time (222) is based on a SFN derived from a counter value generated by a discontinuous counter (124) that is deactivated during the sleep state. In one aspect, the continuous counter (122) may be clocked by a continuous clock (118) during a sleep mode and the discontinuous counter (124) may be clocked by a faster clock (120) that is deactivated during the sleep mode. During reactivation after the sleep mode, the discontinuous counter (120) is set, at the counter set time, to a reset counter value (126) corresponding to an SFN indicated by the continuous counter (122).