| 摘要 |
A mobile communication system that comprises: a base station that manages a cell; a user terminal connectable to the cell; and another user terminal that can communicate, via the base station, with the user terminal, and that supports D2D communication that is direct device-to-device communication, wherein the user terminal starts transmitting a discovery-use signal for the D2D communication when it is determined that the user terminal and the other user terminal exist in the vicinity while the user terminal communicates with the other user terminal connected to a neighbor cell adjacent to the cell. |
