An apparatus for a wireless communication system includes one or more base stations and a plurality of user devices, UEs. The apparatus is configured to be connected to one or more UEs via a sidelink for a sidelink communication with the one or more UEs, the apparatus and the one or more UEs forming a group of UEs and using a set of group resources to be used for the sidelink communication within the group of UEs. In case a base station does not provide resource allocation configuration or assistance, the apparatus is configured to select resources from a set of resources provided by the wireless communication system so as to alter or completely change the set of group resources to be used for the sidelink communication within the group of UEs.