A road-side network node (NN2; NN4; NN5; NN6) for operating in a cell-supported radio communications network, CNET, the road-side network node (NN2; NN4; NN5; NN6) comprising a processor, a memory, a radio module, and an antenna, the road-side network node (NN2; NN4; NN5; NN6) being configured to: - determine or receive a gap information indicating a transmission gap period on a sidelink radio channel; - transmit an energy signature in form of white band noise or an a-priori known signature via the sidelink radio channel within the transmission gap period; - determine an adhoc TDM-channel in dependence on a resource pool, wherein the resource pool comprises information about a sidelink TDM channel and the adhoc TDM channel, each comprising time slices indicating an exclusive reservation for the respective channel, wherein the adhoc TDM-channel is exclusively reserved for communication via the adhoc radio channel, wherein the adhoc TDM-channel is provided by an adhoc network, VANET, and wherein the sidelink TDM channel is provided by the cell-supported radio communications network, CNET, wherein in the cell-supported radio communications network, CNET, and in the adhoc network, VANET, radio signals are transmitted using the same or overlapping unlicensed frequency; - determine the non-sidelink time according to the adhoc TDM-channel and start listening the sidelink radio channel before the end of a time-slice of the adhoc TDM-channel being available for transmitting via the adhoc TDM-channel from a time t_3_1 on, wherein the time t_3_1 is determined as the subsequent subframe border tsub minus an adhoc frame time ft, which can be determined a maximum or mean frame time on the adhoc radio channel; - determine whether the sidelink radio channel is idle; and - transmit a further energy signature in form of white band noise or an a-priori known signature until an end of the time slice of the adhoc TDM-channel when the sidelink radio channel gets idle. - determine or receive a gap information indicating a transmission gap period on a sidelink radio channel; - transmit an energy signature in form of white band noise or an a-priori known signature via the sidelink radio channel within the transmission gap period; - determine an adhoc TDM-channel in dependence on a resource pool, wherein the resource pool comprises information about a sidelink TDM channel and the adhoc TDM channel, each comprising time slices indicating an exclusive reservation for the respective channel, wherein the adhoc TDM-channel is exclusively reserved for communication via the adhoc radio channel, wherein the adhoc TDM-channel is provided by an adhoc network, VANET, and wherein the sidelink TDM channel is provided by the cell-supported radio communications network, CNET, wherein in the cell-supported radio communications network, CNET, and in the adhoc network, VANET, radio signals are transmitted using the same or overlapping unlicensed frequency; - determine the non-sidelink time according to the adhoc TDM-channel and start listening the sidelink radio channel before the end of a time-slice of the adhoc TDM-channel being available for transmitting via the adhoc TDM-channel from a time t_3_1 on, wherein the time t_3_1 is determined as the subsequent subframe border tsub minus an adhoc frame time ft, which can be determined a maximum or mean frame time on the adhoc radio channel; - determine whether the sidelink radio channel is idle; and - transmit a further energy signature in form of white band noise or an a-priori known signature until an end of the time slice of the adhoc TDM-channel when the sidelink radio channel gets idle. <EOS>