Method and apparatus for performing uplink operation for layer 2 mobility in mobile wireless communication system

A terminal in a wireless communication system, the terminal comprising:

• a transceiver configured to transmit and receive a signals;
• and
• a controller configured to control the transceiver to:
• receive, from a base station, a Radio Resource Control (RRC) message, the RRC message comprising:
• a first temporary identifier;
• first Physical Uplink Control Channel (PUCCH)
• configuration;
• and
• second PUCCH configuration;
• receive, from the base station, a first Medium Access Control (MAC) Control Element (CE), wherein the first MAC CE comprising a first field indicating an identifier related to the first PUCCH configuration and a second field related to random access;
• perform a random access procedure in response to the second field being set to a first specific value:
• perform PUCCH transmission based on the first PUCCH configuration;
• receive, from the base station, a second MAC CE, the second MAC CE comprising the first field indicating an identifier related to the second PUCCH configuration and the second field related to random access;
• and
• perform PUCCH transmission based on the second PUCCH configuration,
• wherein the random access procedure is not performed for the second MAC CE based on the second field being set to a second specific value.