Method for activating/deactivating cell in wireless communication system and device therefor

A user equipment (UE) for activating/deactivating a secondary cell (SCell) in a wireless communication system supporting carrier aggregation, the UE comprising:

• a transceiver to transmit and receive radio signals;
• and
• a processor configured to:
• control the transceiver to receive an SCell addition message for adding a plurality of SCells from an eNB;
• partially activate one or more first SCells when a partial activation related message for the one or more first SCells among the plurality of SCells added based on the SCell addition message is received from the eNB;
• fully activate one or more second SCells when a full activation related message for the one or more second SCells among the plurality of SCells added based on the SCell addition message is received from the eNB;
• perform only channel state information (CSI) measurement and/or radio resource management (RRM) measurement of the partially activated one or more first SCells for a handover;
• perform the handover from a specific SCell in the second SCells to a specific SCell in the first SCells;
• and
• switch the specific SCell in the first SCells from being partially activated to being fully activated,
• wherein normal SCell operations are applied to the one or more second SCells and only some of the normal SCell operations are applied to the one or more first SCells, and
• wherein the plurality of SCells is configured to use a same CSI reporting mode and a same CSI reporting resource.