Patent ID: 8811283

Claim:
A method for routing in a base station system a message received from a mobile communication device to a core network, the base station system being connected to at least two core networks, to each core network an identifier being assigned, the method comprising: receiving in the base station system the message from the mobile communication device together with an identifier assigned to a first core network of the core networks, wherein the identifier added to the message by the mobile communication device is determined in the mobile communication device based upon information in a broadcast message broadcasted by the base station system in a radio cell of a shared radio access network in which the mobile communication device is located, wherein the broadcast message broadcasted by the base station system comprises a list of identifiers or a common identifier and additional information indicating that the radio access network is shared; broadcasting a common identifier from the base station system; determining the identifier based upon the common identifier at the mobile communication device; determining the identifier by the mobile communication device using an allocation between the common identifier and the identifier stored in the mobile communication device; reading the identifier in the base station system; and forwarding the message from the base station system to the first core network based upon the read identifier.