Method and apparatus for performing carrier management in carrier aggregation system

1. A method performed by a base station for a carrier configuration and activation in a carrier aggregation system, comprising:

transmitting a first signaling to configure at least one additional carrier to a user equipment (UE) at which the additional carriers are deactivated, and to configure a timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry;

transmitting a second signaling that carries an activation indication to the UE to indicate the UE to activate at least one deactivated additional carrier in the configured carriers for the UE;

activating the at least one deactivated additional carrier and controlling the UE to start Physical Downlink Control Channel (PDCCH) monitoring for the activated additional carrier and Physical Downlink Shared Channel (PDSCH) receiving on the activated additional carrier;

transmitting PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE, by which the timer being restarted; and

deactivating the activated additional carrier after the corresponding timer expiry and controlling the UE to stop the PDCCH monitoring for the activated additional carrier and the PDSCH receiving on the deactivated additional carrier.

2. A method performed by a user equipment (UE) that performs carrier activation in a carrier aggregation system, the method comprising:

receiving a first signaling to configure at least one additional carrier transmitted from a base station, and to configure a timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry;

receiving a second signaling that carries an activation indication to indicate the UE to activate at least one deactivated additional carrier in the configured carriers for the UE; and

activating at least one deactivated additional carrier in the configured carriers for the UE according to the second signaling, and starting the PDCCH monitoring for the additional carrier and PDSCH receiving on the activated additional carrier; and

restarting the timer by PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE; and

deactivating the activated additional carrier after the corresponding timer expiry and stopping the PDCCH monitoring for the activated additional carrier and the PDSCH receiving on the deactivated additional carrier.

3. A base station that performs carrier activation in a carrier aggregation system, comprising:

a transmitting unit that transmit a first signaling to configure at least one additional carrier to a user equipment (UE) at which the additional carriers are deactivated, and to configure a timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry, and transmit a second signaling that carries an activation indication to the UE to indicate the UE to activate at least one deactivated additional carrier in the configured carriers for the UE;

a processor that activates the at least one deactivated additional carrier and controls the UE to start PDCCH monitoring for the activated additional carrier and PDSCH receiving on the activated additional carrier; and

the processor deactivates the activated additional carrier after the corresponding timer expiry and controls the UE to stop the PDCCH monitoring for the additional carrier and the PDSCH receiving on the deactivated additional carrier;

wherein the base station transmits PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE, by which the timer being restarted.

4. A user equipment (UE) in a carrier aggregation system, comprising:

a receiving unit that receives a first signaling to configure at least one additional carrier transmitted from a base station, and to configure a timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry, and receives a second signaling that carries an activation indication to indicate the UE to activate at least one deactivated additional carrier in the configured carriers for the UE;

a processor that activates at least one deactivated additional carrier in a configured carriers for the UE according to the second signaling and starts the PDCCH monitoring for the additional carrier and PDSCH receiving on the activated additional carrier; and

the processor deactivates at least one activated additional carrier after the corresponding timer expiry and stops the PDCCH monitoring for the additional carrier and PDSCH receiving on the deactivated additional carrier;

wherein the UE restarts the timer by PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE.

5. A communication system in which a communication is performed using carrier aggregation, the communication system comprising:

a base station; and

a user equipment;

wherein the base station includes,

a transmitting unit that transmit a first signaling to configure at least one additional carrier to a user equipment (UE) at which the additional carriers are deactivated, and to configure a timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry, and transmit a second signaling that carries an activation indication to the UE to indicate the UE to activate at least one deactivated additional carrier in the configured carriers for the UE;

a first processor that activates the at least one deactivated additional carrier and controls the UE to start PDCCH monitoring for the activated additional carrier and PDSCH receiving on the activated additional carrier; and

the first processor deactivates the activated additional carrier after the corresponding timer expiry and controls the UE to stop PDCCH monitoring for the activated additional carrier and PDSCH receiving on the deactivated additional carrier, and

wherein the base station transmits PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE, by which the timer being restarted; and

wherein the UE includes,

a receiving unit that receives the first signaling, and to configure the timer to each additional carrier for the UE by which the carrier is deactivated after the timer expiry, and receives the second signaling;

a second processor that activates at least one deactivated additional carrier in the configured carriers for the UE according to the second signaling and starts the PDCCH monitoring for the activated additional carrier and PDSCH receiving on the activated additional carrier; and

the second processor deactivates at least one activated additional carrier after the corresponding timer expiry and stops the PDCCH monitoring for the activated additional carrier and PDSCH receiving on the deactivated additional carrier,

wherein the UE restarts the timer by PDCCH, which is on the primary carrier or on one other activated additional carrier, for the activated additional carrier for the UE.