Method and apparatus for transmitting/receiving data on multiple carriers in mobile communication system

A terminal for performing a random access in a mobile communication system supporting carrier aggregation, the terminal comprising:

• a transceiver configured to transmit and receive a signal;
• and
• a controller configured to:
• transmit, on a primary cell, a first random access preamble,
• receive, on the primary cell, a first random access response message corresponding to the first random access preamble,
• transmit, on the primary cell, a first physical uplink shared channel (PUSCH) according to a first uplink grant included in the first random access response message,
• transmit, on a secondary cell, a second random access preamble,
• receive, on the primary cell, a second random access response message corresponding to the second random access preamble,
• determine a transmission power for a second PUSCH based on a transmission power control (TPC) command included in the second random access response, and
• transmit, on the secondary cell, the second PUSCH according to the determined transmission power and a second uplink grant included in the second random access response message.

A base station for supporting a random access in a mobile communication system supporting carrier aggregation, the base station comprising:

• a transceiver configured to transmit and receive a signal;
• and
• a controller configured to:
• receive, on a primary cell, a first random access preamble,
• transmit, on the primary cell, a first random access response message corresponding to the first random access preamble,
• receive, on the primary cell, a first physical uplink shared channel (PUSCH) according to a first uplink grant included in the first random access response message,
• receive, on a secondary cell, a second random access preamble from a terminal,
• transmit, on the primary cell, a second random access response message, including a transmission power control (TPC) command, corresponding to the second random access preamble to the terminal, and
• receive, on the secondary cell, a second PUSCH according to a transmission power of the terminal determined based on the TPC command and a second uplink grant included in the second random access response message.