Thus, in this step, the D2D authorisation module 69 determines whether or not this D2D service is allowed to continue, e.g. by estimating a level of interference caused by the D2D service to other, network authorised communications within the cell(s) controlled by this base station 5. In order to do this, the D2D authorisation module 69 may take account of other relevant information provided internally from the other modules of the base station 5 (such as the communications control module 63, the D2D control module 65, and the interference handling module 67) or externally from other network nodes (e.g. the MME 9, the HSS 10 or the like). For example, the D2D authorisation module 69 may take account of information identifying a priority level for the call (e.g. a high priority level being assigned to an emergency services related call) and/or to make sure that only those D2D services are authorised that are in compliance with applicable network policies (e.g. allowing specific subscriber groups, such as emergency services or specific tariff groups, to have preferential D2D access).

In this example, the D2D authorisation module 69 determines that the D2D communication is allowed to continue, and thus it generates and sends, in step s411 (and/or 411′), a message to the Mobile telephone 3-1 (and/or mobile telephone 3-2), which message authorises the D2D service with the other mobile telephone to continue. The base station 5 is thus able to reserve the communications resources being used for the D2D communication (if the base station has been provided with information identifying those resources) to avoid those resources being used for other communications (e.g. cellular) in the vicinity of the D2D communications thereby avoiding associated interference.