Furthermore, it will be also appreciated that the mobile telephone will continue its network search even after the base station has authorised the on-going D2D service. This might be necessary, e.g. in case the mobile telephone needs to select a new cell to camp on (e.g. due to movement of the mobile telephone or changes in the perceived signal quality within the current cell). The network search might be performed by a mobile phone while it is operating in the RRC Idle mode. Therefore, it will therefore be appreciated that steps s403 and s503 may be performed independently of the D2D operation of the mobile telephone.

A skilled person would thus also understand that steps s405 and s505 (also s405′ and s505′), in which the mobile telephone indicates an on-going D2D service to the base station, might be repeated every time a new cell or a new base station is found. In this case, the authorisation of the D2D service by the base station (i.e. steps s409 to s411/s411′ and s509 to s511/s511′) might also be repeated every time an indication of the on-going D2D service is received (by the same or a different base station) or even without receiving such an indication. In one alternative, an already authorised D2D service is subsequently switched over to a cellular service by the same or a different base station. This way the base station ensures that interference is kept minimised or eliminated not only at the time of receiving the D2D service indication (i.e. steps s405, s405′, s505, s505′) but continuously, even after authorising the D2D service. This might be particularly beneficial when changing signal or load conditions within the cell(s) of the base station necessitate using a cellular service instead of the current D2D service.