A radio terminal (controller) executes one of a first control, a second control, and a third control, based on at least one of a reception level of a radio signal from a predetermined cell and a transmission level of the radio terminal. In the first control, the radio terminal directly transmits uplink information to be transmitted to a predetermined cell to the predetermined cell, and directly receives downlink information to be received by the radio terminal from the predetermined cell. In the second control, the radio terminal transmits the uplink information to the predetermined cell via a relay terminal configured to execute a relay using a proximity-based service, and directly receives the downlink information from the predetermined cell. In the third control, the radio terminal transmits the uplink information to the predetermined cell via the relay terminal, and receives the downlink information from the predetermined cell via the relay terminal.