Method and apparatus for performing uplink timing synchronization procedure upon handover in a mobile communication system

摘要

An efficient uplink timing synchronization procedure performed with a target cell upon handover of a User Equipment (UE) in active mode in a mobile communication system is provided, in which a cell transmitter signals to the UE that the uplink timing synchronization procedure is not required in the target cell, and the UE carries out uplink transmission to the target cell at an uplink timing used in a source cell without the uplink timing synchronization procedure.