MOBILE COMMUNICATION SYSTEM, USER TERMINAL, BASE STATION, PROCESSOR, AND COMMUNICATION CONTROL METHOD

摘要

A mobile communication system includes a base station and a first user terminal and a second user terminal that establish a connection with the base station. When the first user terminal starts D2D communication, which is direct device to device communication, with the second user terminal, the first user terminal notifies the base station of an amount of specific data transmitted preferably in the D2D communication.