Techniques for implementing proper transmission of RA preambles in a RA procedure are disclosed. An aspect of the present invention relates to a base station including a communication control unit configured to control radio communication with user equipment; and an RA procedure processing unit configured to perform a random access (RA) procedure with the user equipment, wherein the RA procedure processing unit indicates to the user equipment a maximum multiplexing number of RA preambles multiplexed into a radio resource capable of transmitting the RA preambles.