In a method in a central node of a cellular radio network the central node is adapted to deciding if a mobile station connected to the cellular radio network via a first radio access technology controlled by the central node is to be moved to another radio access technology when a circuit switched call of the mobile station is ended. The two photons are directed through a beam splitter that directs each photon to one of two transmission lines, which lead to two respective receivers. In a case wherein the user selects to interact with the virtual environment, an avatar is determined for interaction with the virtual environment. The data processing apparatus also has the capability of operating in an adequate process mode corresponding to a process command contained in a received packet.