METHOD FOR A USER TERMINAL TO RANDOM ACCESS A CARRIER AGGREGATION MOBILE COMMUNICATION SYSTEM

摘要

A method for random access to a base station by a user equipment (UE) in a mobile communication system using carrier aggregation in which communication is conducted over a plurality of component carriers, and a terminal for the method are disclosed. When the UE performs a contention-based random access procedure in the mobile communication system to which CA technology is applied, the UE considers an uplink grant signal as a contention resolution message when receiving the uplink grant signal from a eNB only when the uplink grant signal is received through a downlink CC corresponding to an uplink CC used to transmit a random access preamble or a third message, to thereby prevent contention resolution from being erroneously ended.

主权项

1. A method for performing a random access procedure with a User Equipment (UE) in a mobile communication system supporting carrier aggregation using a primary carrier and one or more secondary carriers, the method performed by a Base Station (BS) and comprising:
receiving, from the UE, a first message comprising a random access preamble through the primary carrier; transmitting, to the UE, a second message including first uplink (UL) grant information as a response to the random access preamble through the primary carrier; receiving, from the UE, a third message including identity information of the UE through an uplink radio resource corresponding to the first UL grant information; and transmitting, to the UE, a Physical Downlink Control Channel (PDCCH) indicated by the identity information of the UE, wherein, when the PDCCH is transmitted through the primary carrier, a contention resolution procedure according to transmission of the third message is considered as a successful procedure, and wherein, when the PDCCH is transmitted through the one or more secondary carriers, the contention resolution procedure is considered as an unsuccessful procedure.