Methods for controlling SCell state and apparatuses thereof

1. A method of controlling states of a secondary cell (SCell) by a user equipment, the method comprising:

receiving SCell state indication information indicating a state for the SCell from a base station through a radio resource control (RRC) message or a medium access control (MAC) control element;

configuring the state of the SCell in one of an activation state and a dormant state based on the SCell state indication information; and

transmitting channel state information for the SCell to the base station in accordance with channel quality indicator (CQI) configuration information configured for the SCell,

wherein the transmitting comprises:

transmitting channel state information for the SCell to the base station by applying a value of a first activation state CQI report parameter contained in a first CQI configuration information when the first CQI configuration information for the SCell is configured in the user equipment, and

transmitting channel state information for the SCell to the base station by applying a value of a second CQI report parameter contained in second CQI configuration information when the first CQI configuration information is not configured in the user equipment, and

wherein:

the first CQI configuration information and the second CQI configuration information comprise different CQI report periods and offset values; and

the CQI report period contained in the first CQI configuration information is set as a shorter value than the CQI report period contained in the second CQI configuration information.

2. The method of claim 1 , wherein the configuring comprises:

configuring the SCell in the activation state when the SCell state indication information indicates the activation state, and

starts or restarts a SCell dormant timer when the SCell dormant timer is configured in association with the SCell.

3. The method of claim 1 , wherein the transmitting comprises transmitting the channel state information in accordance with the second CQI configuration information when the first CQI configuration information is expired and when the channel state information in accordance with the first CQI configuration information is transmitted.

4. The method of claim 3 , wherein when the number of a subframe receiving SCell state indication information indicating an activation state for the SCell is n, the first CQI configuration information is expired at a transmission time interval (TTI) comprising an n+34 subframe.

5. The method of claim 2 , wherein the configuring comprises changing the state of the SCell into the dormant state and stopping a SCell deactivation timer associated with the SCell when a SCell dormant timer associated with the SCell is expired.

6. The method of claim 1 , wherein the configuring comprises:

configuring the SCell in the dormant state when the SCell state indication information indicates the dormant state;

stopping a SCell deactivation timer associated with the SCell; and

starting or restarting a dormant SCell deactivation timer when the dormant SCell deactivation timer is configured in association with the SCell.

7. The method of claim 6 , wherein the transmitting comprises transmitting channel state information for the SCell to the base station in accordance with a CQI report parameter value contained in dormant state CQI configuration information distinct from first CQI configuration information and second CQI configuration information that are applied in the activation state.

8. The method of claim 6 , wherein the dormant SCell deactivation timer is not applied to a SCell set to transmit an uplink control channel.

9. A method of controlling states of a secondary cell (SCell) of a user equipment by base station, the method comprising:

transmitting secondary cell (SCell) state indication information indicating a state for a SCell to the user equipment through one of a radio resource control (RRC) message and a medium access control (MAC) control element; and

receiving channel state information for the SCell in accordance with channel quality indicator (CQI) configuration information configured for the SCell when the state of the SCell is configured in an activation state or a dormant state on the basis of the SCell state indication information,

wherein when the state of the SCell is configured in the activation state, the receiving comprises:

receiving channel state information for the SCell in accordance with a value of a first activation state CQI report parameter contained in a first CQI configuration information when the first CQI configuration information for the SCell is configured in the user equipment, and

receiving channel state information for the SCell in accordance with a value of a second CQI report parameter contained in second CQI configuration information when the first CQI configuration information is not configured in the user equipment, and

wherein the receiving comprises receiving the channel state information in accordance with the second CQI configuration information when the first CQI configuration information configured in the user equipment is expired and when the channel state information in accordance with the first CQI configuration information is received.

10. The method of claim 9 , wherein when the state of the SCell is configured in the dormant state, the receiving comprises receiving channel state information for the SCell in accordance with a CQI report parameter value contained in dormant state CQI configuration information distinct from first CQI configuration information and second CQI configuration information that are applied in the activation state.

11. A user equipment for controlling states of a secondary cell (SCell) by a user equipment, the user equipment comprising:

a receiver configured to receive SCell state indication information indicating a state for the SCell from a base station through one of a radio resource control (RRC) message and a medium access control (MAC) control element;

a controller configured to control the state of the SCell in one of an activation state and a dormant state based on the SCell state indication information; and

a transmitter configured to transmit channel state information for the SCell to the base station in accordance with channel quality indicator (CQI) configuration information configured for the SCell,

wherein the transmitter is configured to:

transmit channel state information for the SCell to the base station by applying a value of a first activation state CQI report parameter contained in a first CQI configuration information when the first CQI configuration information for the SCell is configured in the user equipment; and

transmit channel state information for the SCell to the base station by applying a value of a second CQI report parameter contained in second CQI configuration information when the first CQI configuration information is not configured in the user equipment, and

wherein the first CQI configuration information and the second CQI configuration information comprise different CQI report periods and offset values, and the CQI report period contained in the first CQI configuration information is set as a shorter value than the CQI report period contained in the second CQI configuration information.

12. The user equipment of claim 11 , wherein the controller is configured to:

configure the SCell in the activation state when the SCell state indication information indicates the activation state; and

start or restart a SCell dormant timer when the SCell dormant timer is configured in association with the SCell.

13. The user equipment of claim 11 , wherein the transmitter is configured to transmit the channel state information in accordance with the second CQI configuration information when the first CQI configuration information is expired, when the transmitting step transmits the channel state information in accordance with the first CQI configuration information.

14. The user equipment of claim 11 , wherein the controller is configured to:

configure the SCell in the dormant state when the SCell state indication information indicates the dormant state;

stop a SCell deactivation timer associated with the SCell; and

start or restart a dormant SCell deactivation timer when the dormant SCell deactivation timer is configured in association with the SCell.