A communication system (100, 200), comprising: a plurality of mobile communication networks, wherein each mobile communication network comprises a gateway device (202, 202'), a terminal device (211, 211') and one or more further network entities (205a, b, 203, 204a, b, 351), and a remote sidelink control server configured to communicate with the gateway device of each of the plurality of mobile communication networks on the basis of user plane signaling, wherein the gateway device of one of the plurality of mobile communication networks is configured to transform user plane signaling from the remote sidelink control server, related to the control of sidelink communication services and/or resources of the one mobile communication network, into control plane signaling, and provide the control plane signaling to the terminal device (211, 211') and one or more of the further network entities (205a, b, 203, 204a, b, 351) of the one mobile communication network, wherein said system is configured to enable a coordination, among the plurality of mobile communication networks, for access to shared resources and applications, and a provision of UE connectivity parameters without exposing the one mobile communication network's topology to an external network; wherein the one or more further network entities (205a,b, 203, 204a,b, 351) of the one mobile communication network comprise a local sidelink control server of the mobile communication network; and wherein the gateway device (202, 202') of the one of the plurality of mobile communication networks is configured to transform user plane signaling from the remote sidelink control server related to a registration request of the remote sidelink control server into control plane signaling, and to provide said control plane signaling to the local sidelink control server for registering the remote sidelink control server in a repository of registered applications at the local sidelink control server. a plurality of mobile communication networks, wherein each mobile communication network comprises a gateway device (202, 202'), a terminal device (211, 211') and one or more further network entities (205a, b, 203, 204a, b, 351), and a remote sidelink control server configured to communicate with the gateway device of each of the plurality of mobile communication networks on the basis of user plane signaling, wherein the gateway device of one of the plurality of mobile communication networks is configured to transform user plane signaling from the remote sidelink control server, related to the control of sidelink communication services and/or resources of the one mobile communication network, into control plane signaling, and provide the control plane signaling to the terminal device (211, 211') and one or more of the further network entities (205a, b, 203, 204a, b, 351) of the one mobile communication network, wherein said system is configured to enable a coordination, among the plurality of mobile communication networks, for access to shared resources and applications, and a provision of UE connectivity parameters without exposing the one mobile communication network's topology to an external network; wherein the one or more further network entities (205a,b, 203, 204a,b, 351) of the one mobile communication network comprise a local sidelink control server of the mobile communication network; and wherein the gateway device (202, 202') of the one of the plurality of mobile communication networks is configured to transform user plane signaling from the remote sidelink control server related to a registration request of the remote sidelink control server into control plane signaling, and to provide said control plane signaling to the local sidelink control server for registering the remote sidelink control server in a repository of registered applications at the local sidelink control server.