A user terminal according to a first aspect is used in a mobile communication system which supports a D2D proximity service for enabling direct device-to-device communication. The user terminal comprises a controller configured to obtain mapping information indicating a correspondence relationship between a D2D application and a frequency to be used for the D2D application, the D2D application being an application of the D2D proximity service. The controller determines the frequency to be used for the D2D application based on the mapping information.