A base station in a mobile communication system containing a user equipment and the base station that includes an uplink (UL) resource management unit that allocates a plurality of parameters related to a physical uplink control channel (PUCCH) resource used for transmission processing, between the user equipment and the base station; a reception processing unit that receives a signal sent from the user equipment including a transmission processing unit that performs transmission processing based on transmission timing adjustment information; and a control unit that, if a valid term of first transmission timing adjustment information expires before transmission processing of a signal including identification information of the user equipment is performed during connection processing while performing the connection processing to the base station based on the first transmission timing adjustment information, aborts the connection processing and releases at least one of the allocated plurality of parameters related to the PUCCH resource.