Random access method and apparatus of UE in mobile communication system

A terminal for performing random access, the terminal comprising:

• a controller configured to determine whether a Scheduling Request (SR) is pending, determine, when the SR is pending, whether an uplink transmission resource is available in a current Transmission Time Interval (TTI), determine, when the uplink transmission resource is not available, whether a Physical Uplink Control Channel (PUCCH) resource is configured to transmit the SR, and initiate, when the PUCCH resource is not configured, a random access process in a primary cell,
• wherein the controller determines, when the PUCCH resource is configured, whether the PUCCH resource is configured to transmit the SR in the current TTI and whether the current TTI is not a part of a measurement gap and whether a timer is not running, compares, when the PUCCH resource is configured to transmit the SR in the current TTI and the current TTI is not a part of the measurement gap and the timer is not running, an SR transmission times counter with a threshold value of SR transmission, and initiates, when the SR transmission, times counter is equal to or greater than the threshold value of SR transmission, the random access process in the primary cell.