User equipment and method

User equipment having a dual connectivity function to communicate with a master base station and a secondary base station simultaneously, comprising:

• a transmission and reception unit configured to transmit and receive radio signals to/from the master base station and the secondary base station;
• an RA processing unit configured to perform a random access (RA) procedure;
• and
• a timer management unit configured to activate a timer upon detecting an RA procedure activation event for triggering activation of the RA procedure for the secondary base station,
• wherein a period configured for the timer is indicated from the master base station,
• wherein if the RA procedure performed in response to detection of the RA procedure activation event has not been completed before expiration of the timer, the timer management unit indicates to the triggering base station that the RA procedure has not been completed, and
• wherein even upon exceeding a maximum number of retransmissions of a PRACH (Physical Random Access Channel), the RA processing unit continues in retransmitting the PRACH during activation of the timer.