A user equipment (UE) has established a first radio link with a serving network node and a second device-to-device (D2D) radio link directly with another user equipment (UE). In response to having D2D data to send to the other UE over the D2D radio link, the UE sends to the serving network node on the first link a request for radio resources for a layer 1 (L1) control channel; and in response to an assignment of D2D resources by the serving network node in reply to that request, the UE sends on the assigned D2D resources to the other UE the D2D data and the L1 control channel. In one example the request includes an indication of the UE's link adaptation for the L1 control channel such as format for a PDCCH or ePDCCH and/or aggregation level.