Disclosed herein is a method for reporting existence of an isolated radio access network and a wireless device and a radio base station for performing the method. The method comprises: performing communications in an isolated radio access network, the isolated radio access network being a radio access network provided by one or more first radio base stations that do not have connectivity to a centralized core network of a cellular communications network; attaching to a second radio base station, the second radio base station having connectivity to the core network; and providing, to a centralized communications server via the second radio base station, one or more messages that inform the centralized communications server of the existence of the isolated radio access network.