Patent attributes
A mobile communication system according to the present invention supports cellular communication in which a data path passes through a core network and D2D communication that is direct device-to-device communication in which a data path does not pass through the core network. The mobile communication system has a user terminal that performs a process of discovering a partner terminal in the D2D communication or performs the D2D communication. A plurality of radio resources that are the time-frequency resources that can be used for the process of discovering or the D2D communication consist of radio resources associated with transmission power used for the process of discovering or the D2D communication. The user terminal performs the process of discovering or the D2D communication on the basis of the transmission power associated with the radio resource used by the user terminal.