METHOD AND APPARATUS FOR MAINTAINING UPLINK TIMING SYNCHRONIZATION IN MOBILE COMMUNICATION SYSTEM

摘要

A method for maintaining UL timing synchronization in a mobile communication system and a terminal device thereof are provided to store UL timing and DL timing separately as reference UL timing and reference DL timing when initial UL timing synchronization is acquired, calculate periodically DL timing, compare the DL timing with the reference DL timing to calculate a difference, and maintain the UL timing by applying the difference to the reference UL timing, thereby reducing the overhead of signaling of UL and DL and using efficiently radio resource by reducing signaling frequency between an UE(User Equipment) and an E-NB(Evolved-Node B). A method for maintaining UL(Uplink) timing synchronization comprises the following steps of: controlling UL timing according to UL timing control information included in a response message from a BS(Base Station) and storing the controlled UL timing as reference UL timing for UL signaling or data transmission(431); measuring periodically DL(Downlink) timing after storing the reference UL timing and calculating a difference between the measured DL timing and pre-stored reference DL timing(441,451); and determining the UL timing by using the calculated difference with the DL timing and the reference UL timing(481).