A radio station (1) is configured to transmit to a radio terminal (3), on a licensed frequency (Cell #1), a notification regarding detection of proximity to a non-serving cell (Cell #2) on an unlicensed frequency (S102) and to receive from the radio terminal (3), on the licensed frequency (Cell #1), a result of the detection performed by the radio terminal (3) in response to the notification. This contributes, for example, to acquisition of information useful for the radio station to determine whether to allow the radio terminal to perform communication on the unlicensed frequency.