Patent ID: 8331401

Claim:
A method of controlling uplink transmission at a user equipment in a wireless communications system, wherein the user equipment is configured with multiple component carriers, the method comprising: receiving configuration information for transmitting an uplink signal from a base station, the configuration information including information for periodically transmitting the uplink signal to the base station; and performing operations for periodically transmitting the uplink signal to the base station on a corresponding uplink component carrier in use of the configuration information, wherein if the corresponding uplink component carrier is in an available state at a time for transmitting the uplink signal, the uplink signal is transmitted on the corresponding uplink component carrier at the time, wherein if the corresponding uplink component carrier is in a non-available state at a time for transmitting the uplink signal, the uplink signal is not transmitted on the corresponding uplink component carrier at the time, and wherein whether or not the corresponding uplink component carrier is in a non-available state is identified by using a state of a downlink component carrier linked to the corresponding uplink component carrier.