Use of wireless circuit-switched connections for the real-time transmission of packet switched multimedia services

摘要

The present invention relates to a system and method for connecting wireless circuit-switched bearer services of a public mobile phone system to the transfer of information requiring real-time operation of packet-switched multimedia services. The system according to the invention comprises a terminal, a wireless access network, a multimedia core network and a network device, which connects the wireless access network to the multimedia core network, adapts a so-called expanded location updating to the registration procedure of the multimedia core network, and performs double registration of the user to the multimedia core network. The terminal performs the above-mentioned expanded location updating, where it relays the registration point identity of the multimedia core network, the user's phone number and the private user identity to the network device in connection with normal location updating signaling. In the double registration performed by the network device, two addresses are registered for the user of the terminal, one of which is associated with the domain name of the terminal in question or a numeric IP address, and the other to a domain name of the network device or a numeric IP address. After this the use of circuit-switched bearer services for transferring information requiring real-time operation of packet-switched multimedia services takes place in such a manner that first the terminal establishes both the packet-switched connection directly to the multi service network, and a circuit-switched connection between the terminal and the network device, which circuit-switched connection is established by contacting the phone number of the user of the terminal in question, after which the terminal can transfer the information requiring real-time operation over the circuit-switched connection between the terminal and the multimedia core network.