Conversational bearer negotiation

• US 7,876,743 B2
• Filed: 02/12/2004
• Issued: 01/25/2011
• Est. Priority Date: 02/15/2003
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Suotula, Janne, Garcia-Martin, Miguel-Angel
• Primary Examiner(s): Gauthier; Gerald
• Application Number:
  US10/777,407
• Publication Number:
  US 20040249887A1
• Time in Patent Office: 2,539 Days
• Field of Search: 370353-356, 370/359, 370/235, 370/313, 370/338, 370/352, 370/381, 370/401, 370/390, 379/219, 379/88.26, 455/445, 455/414, 455/432, 709/204, 726/22
• US Class Current: 370/352
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1095 Inter-network session transfer or sharing
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04M 2207/18 wireless networks
• CPC Class Codes: H04M 2207/20 hybrid systems
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/0093 signalling arrangements in networks
• CPC Class Codes: H04M 7/123 where the packet-switched network is an Internet Protocol Multimedia System-type network

Abstract

A method of setting up a session between peer user terminals of a communication system, wherein at least one of the user terminals is a dual-mode terminal having access to both an IP-based packet-switched access network and a circuit-switched access network, and the session extends at least in part across the circuit-switched access network. One of the user terminals initiates the session by sending Session Initiation Protocol (SIP) signaling to a SIP server over the IP-based network. The SIP server sends a notification to a gateway server to establish one or more conversational bearers. The gateway server then sends a callback telephone number to the dual-mode terminal. The dual-mode terminal then calls the callback number to establish a circuit-switched session with the gateway server.

Claims

1. A method of setting up a session between first and second peer user terminals of a communication system, wherein at least one of the peer user terminals is a dual-mode mobile terminal having access to an Internet Protocol (IP) based packet switched network and a circuit switched access network, said session extending at least in part across the circuit switched access network, the method comprising the steps of:

transporting signaling to initiate the session via the IP based packet switched network using a call control protocol which is also used for setting up end-to-end packet switched sessions, the signaling being Session Initiation Protocol (SIP) signaling exchanged between the dual mode mobile terminal and a SIP server of an IP Multimedia Core Network Subsystem (IMS);

sending a notification from the SIP server to a gateway server that one or more conversational bearers must be established, the gateway server terminating the circuit switched session within the system;

after notification from the SIP server, sending from the gateway server to the dual-mode mobile terminal, a callback telephone number; and

calling the callback telephone number by the dual-mode mobile terminal to establish a circuit switched call with the gateway server.

2. The method according to claim 1, further comprising utilizing the circuit switched call to provide the one or more conversational bearers.

3. The method according to claim 2, further comprising utilizing the packet switched session to provide non-conversational bearers established over said IP based packet switched network.

4. The method according to claim 1, wherein said SIP server and said gateway server are co-located.

5. The method according to claim 1, wherein the gateway server provides interworking between the circuit switched call and the packet switched session.

6. The method according to claim 1, wherein at least one peer user terminal is notified of the callback telephone number via the SIP server.

7. The method according to claim 6, wherein the gateway server maps the established circuit switched call to the packet switched session based on the callback telephone number.

8. The method according to claim 1, wherein the gateway server selects the callback telephone number from a pool of available callback numbers.

9. The method according to claim 1, further comprising determining by the SIP server that the packet switched session requires setting up a circuit switched call as a result of one or more of the following:

properties of the system known to the SIP server;

prior notification by at least one of the peer user terminals;

information contained in the SIP signaling initiating the packet switched session;

properties defined for at least one of the peer user terminals;

prior notification from a visited network if one of the peer user terminals is roaming; and

prior notification from the packet switched access network used by one of the peer user terminals.

10. A Session Initiation Protocol (SIP) server for use in an Internet Protocol (IP) Multimedia Core Network Subsystem, the server comprising:

means for receiving an INVITE request from a dual-mode user terminal, over an IP based packet switched domain, initiating a packet switched session;

means for determining that the packet switched session requires setting up of at least one circuit switched conversational bearer over a circuit switched access network serving the dual-mode user terminal;

means for sending a notification from the SIP server to a gateway server that one or more conversational bearers must be established, the gateway server terminating the circuit switched session within the system; and

means for receiving a callback telephone number from the gateway server and for forwarding the callback number to the dual-mode terminal.

11. A gateway server for providing an interface between a circuit switched access network and a packet switched network, the gateway server having an interface towards a Session Initiation Protocol (SIP) server of an Internet Protocol (IP) Multimedia Core Network Subsystem, said gateway server comprising:

means for receiving from the SIP server, signaling instructing the setting up of a circuit switched call over the circuit switched access network with a dual-mode user terminal;

means for sending a callback number to the dual-mode user terminal in response to receipt of the signaling; and

means for terminating a call made to the callback number by the dual-mode user terminal.