A user terminal and method thereof transmit a notification to a base station before starting direct device to device (D2D) communication, where the notification indicates a desire for performing the D2D communication, transmitting to the base station a measurement report including results of measurement of a cell reference signal, transmitting to the base station a data amount notification indicating an amount of data to be transmitted from the first user terminal to a second user terminal, and using radio resources allocated from the base station, where the radio resources are used by the first user terminal to transmit the data to the second user terminal. A base station operates to receive the above notifications and measurement report from the user terminal and allocate radio resources used by the user terminal to transmit the data to the second user terminal.