Method of handling uplink synchronization and related communication device

摘要

A method of handling uplink synchronization for a mobile device capable of receiving and transmitting on a plurality of component carriers in a wireless communication system is disclosed. The method comprises managing a plurality of time alignment timers, each timer corresponding to some of the plurality of component carriers for indicating a synchronization state on the component carriers with the same timing advance value, wherein the managing step comprises: starting or restarting the time alignment timer when a timing advance command in a random access response message of a random access procedure is received for a first component carrier, and a random access preamble of the random access procedure is not selected by the mobile device or the time alignment timer is not running; and performing the random access procedure on the first component carrier of the component carriers with the same timing advance value.