Method and apparatus for performing and reporting measurements by user equipment configured with multiple carriers in mobile communication systems

A method by a base station in a wireless communication system supporting carrier aggregation, the method comprising:

• transmitting to a terminal a control message including indication information, the indication information indicating that physical uplink control channel (PUCCH) feedback for at least one secondary cell (SCell) is transmitted on a SCell;
• and
• receiving from the terminal a message including Type 2 power headroom information for the SCell,
• wherein the Type 2 power headroom information is included in the message if the SCell is configured to the terminal and is activated.

A terminal in a wireless communication system supporting carrier aggregation, the terminal comprising:

• a transceiver configured to transmit and receive signals;
• and
• a controller configured to:
• control a reception of a control message including indication information, the indication information indicating that physical uplink control channel (PUCCH) feedback for at least one secondary cell (SCell) is transmitted on a SCell,
• identify whether the SCell is configured to the terminal and is activated,
• if the SCell is configured to the terminal and is activated, obtain Type 2 power headroom information for the SCell.

A base station in a wireless communication system supporting carrier aggregation, the base station comprising:

• a transceiver configured to transmit and receive signals;
• and
• a controller configured to:
• transmit to a terminal a control message including indication information, the indication information indicating that physical uplink control channel (PUCCH) feedback for at least one secondary cell (SCell) is transmitted on a SCell;
• and
• receive from the terminal a message including Type 2 power headroom information for the SCell,
• wherein the Type 2 power headroom information is included in the message if the SCell is configured to the terminal and is activated.