When completing radio communication with a radio terminal, a transmitting unit of a base station transmits to the radio terminal a validity period of control information on radio communication which has been used to communicate with the radio terminal. When starting radio communication with the radio terminal within the validity period, a communication unit of the base station performs radio communication with the radio terminal without performing a process of exchanging control information. When completing radio communication with the base station, a receiving unit of the radio terminal receives a validity period from the base station. When starting radio communication with the base station within the validity period, a communication unit of the radio terminal performs radio communication with the radio terminal without performing a process of exchanging control information.