Patent ID: 8811350
Filing Date: 2014-08-19
Classification: H04J,H04L,H04W

Abstract:
1. A method for performing a handover at a user equipment (UE) in a wireless mobile communication system which supports carrier aggregation, the method comprising: transmitting, by the UE to a serving base station, a measurement report for a target base station; receiving, by the UE from the serving base station, a handover command message, wherein the handover command message contains allocation information of a plurality of Downlink Component Carriers (DL CCs) available at the target base station, and wherein one of the plurality of DL CCs is allocated as a primary DL CC; and transmitting, by the UE to the target base station, a random access preamble via a specific Uplink CC (UL CC), wherein the specific UL CC is one of UL CCs which are configured at the target base station, and wherein the specific UL CC is a UL CC paired with the primary DL CC in a frequency division duplex system and the specific UL CC is same as the primary DL CC in a time division duplex system.