A base station assigns a first set of device-to-device (D2D) communication resources to a first D2D group and assigns a second set of D2D communication resources to a second D2D group. The D2D communication resources of the first set are different from the D2D communication resources of the second set. The first set of D2D communication resources and the second set of D2D communication resources are subsets of reserved D2D communication resources which are a subset of defined uplink communication resources defined by a communication specification for uplink communication between the D2D UE devices and a base station where the reserved D2D communication resources not used for uplink transmission to the base station.