Method and apparatus for performing discontinuous reception and/or discontinuous transmission for a multi-carrier/multi-cell operation

A wireless transmit/receive unit (WTRU) comprising:

• a transceiver;
• and
• a processor operatively connected to the transceiver;
• wherein:
• the transceiver configured to receive configuration information indicating a first cell group and a second cell group, and indicating discontinuous reception (DRX) information for the first cell group and the second cell group;
• the transceiver configured to receive a command associated with DRX;
• the transceiver and the processor configured to perform, based on the command associated with DRX, DRX for cells of the first cell group and DRX for cells of the second cell group, wherein a first active time for the first cell group differs from a second active time for the second cell group, wherein one or more cells within the first cell group are active during the first active time and one or more cells within the second cell group are active during the second active time;
• the transceiver configured to receive a first command to deactivate a first cell of the first cell group;
• the transceiver and the processor configured to deactivate the first cell based on the first command to deactivate;
• the transceiver configured to receive the first cell based on the first command to deactivate;
• and
• the transceiver and the processor configured to reactivate the deactivated first cell based on the first command to reactivate.