A mobile radio communication system and method of initiating a circuit-switched service at a mobile station over a System Architecture Evolution (SAE) core network using packet-switched communications between the mobile station and the SAE core network is provided. The method includes communicating service handling information between a Mobile Switching Centre (MSC) and the mobile station through a Mobility Management Entity (MME) of the SAE core network; sending instructions from the MSC for setting up the circuit-switched service through a Media Gateway, coupled to at least one network external to the SAE core network; providing packet-switched addressing information for the Media Gateway to the mobile station; and initiating the circuit-switched service at the mobile station over the SAE core network and through the Media Gateway.