Ki Bum Kwon

TL;DR: In this article, the authors proposed a method for uplink synchronization in a multi-component carrier system, which comprises the steps of: receiving, from a base station, a message that indicates a time alignment value for adjusting an uplink time of a sub-serving cell; adjusting the uplink times on the basis of the alignment value; and driving a validity timer, which indicates the period of validity of the time alignment values when the sub-serving cell is deactivated.

TL;DR: In this paper, the authors describe an apparatus and method for performing random access in a wireless communication system, which discloses a mobile station including a reception unit for receiving TAG configuration information on which at least one serving cell configured in the mobile station is classified as a Timing Alignment Group (TAG) from a base station and a transmission unit for transmitting a random access preamble to the base station on one representative serving cell within the TAG.

TL;DR: In this article, a method for performing a random access in a multi-carrier system includes transmitting a preamble on an uplink component carrier to a base station, and receiving a response response on a first downlink component carrier.

TL;DR: In this article, an apparatus and a method for performing a random access in a wireless communication system are provided, which includes transmitting a preamble on at least one serving cell to a base station; and receiving a response message including a plurality of timing advance information applied to each of the at least single serving cell and information on a serving cell on which the plurality of time advance information is applied as a response to the random access preambble from the base station.

TL;DR: In this article, a handover protocol in a multiple component carrier system is proposed, where a UE transmits a measurement report message, including measurement values for one or more cells, to a source BS.