A base station (2) is configured to schedule radio resources to device-to-device (D2D) transmissions (101A, 101B and 101C) performed by D2D communication pairs (3A, 3B and 3C) in accordance with an allocation rule that permits two D2D communication pairs (3A and 3C) that are not in proximity to each other to share an identical radio resource but prohibits two D2D communication pairs (3A and 3B) in proximity to each other from sharing an identical radio resource. Each D2D transmission (101) includes wirelessly transmitting from one radio terminal (1) directly to the other radio terminal (1) in each D2D communication pair (3) without passing through the base station (2). It is, thus, possible to enable efficient spatial reuse of radio resources in D2D transmissions performed by D2D communication pairs.