Patent ID: 6564046
Filing Date: 2003-05-13
Classification: H04W,Y02D

Abstract:
A method of keeping a local time-base in a mobile terminal synchronized with a network time-base during a network IDLE transmission period, the method comprising the steps of:a) determining a mobile terminal IDLE period in high frequency oscillator units associated with a local high frequency oscillator; b) starting a mobile terminal gauging counter clocked by a local low frequency oscillator before commencement of the IDLE transmission period; c) sampling the network time-base at the end of a data transmission period via the local high frequency oscillator to determine a sampled time-base value TSLEEP associated with commencement of the network IDLE transmission period; d) starting a mobile terminal IDLE period counter clocked by the local low frequency oscillator and simultaneously stopping the local high frequency oscillator at time TSLEEP; e) stopping the IDLE period counter upon completion of the IDLE period; f) generating a network time-base value TWAKE-UP upon completion of the IDLE period and determined via an algorithmic relationship between the sampled time-base value TSLEEP, local low frequency oscillator clock cycles C counted by the IDLE period counter during the IDLE period, and a most recent previously determined gauging factor Restimated; g) recovering the mobile terminal local time-base from the network time-base value TWAKE-UP and demodulating communication data received from the network terminal using the recovered local time-base; h) stopping the gauging counter upon recovery of the network time-base and determining an elapsed count value C associated with the gauging counter; i) generating a new gauging factor Restimated in local high frequency oscillator period units for the local low frequency oscillator; and j) repeating continuously steps b-i to maintain synchronization between the mobile terminal local time-base and the network time-base.