Method of and a system for establishing a call over an IP multi media communications system and a circuit switched communications system

• US 8,879,539 B2
• Filed: 04/26/2007
• Issued: 11/04/2014
• Est. Priority Date: 04/26/2007
• Status: Expired due to Fees

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Noldus, Rogier August Caspar Joseph, den Hartog, Jos
• Primary Examiner(s): ADHAMI, MOHAMMAD SAJID
• Application Number:
  US12/597,725
• Publication Number:
  US 20100118862A1
• Time in Patent Office: 2,749 Days
• Field of Search: None
• US Class Current: 370/352
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 80/10 adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14

Abstract

A system and method for simultaneously supporting IMS signaling and Circuit Switched signaling during a call between a calling user terminal in an IP Multi media System (IMS) and a called user terminal in a Circuit Switched CS network. A first IP address is determined by the calling user terminal, the calling user terminal initiates the call using IMS signaling towards the called user terminal, the IMS signaling comprising the first IP address. The called user terminal then initiates a CS connection towards an IP Access Converter using CS signaling and comprising the first IP address. The IP Access Converter allocates a second IP address (IP2) to be used for data transfer with the calling user terminal. The IP Access Converter establishes the CS connection by providing said second IP address to the called user terminal using CS signaling and the called user terminal establishes the call, providing said second IP address to said calling user terminal using IMS signaling. Data transfer occurs between the calling user terminal and the IP Access Converter using the first IP address and second IP address, and between the IP Access Converter and the called user terminal through the CS connection.

Claims

1. A method of data transfer between a first user terminal, arranged for supporting connections in a first Circuit Switched (CS) network and for simultaneously supporting Internet protocol Multi media System (IMS) signaling and CS signaling, and a second user terminal, arranged for supporting sessions and IMS signaling in an IMS, wherein said first CS network comprises a first Internet Protocol (IP) access converter arranged for supporting data transfer in said first CS network and in an IP network, said method comprising the steps of:

receiving from a media gateway a third IP address at the IP access converter;

delivering by said first IP access converter to a mobile switching center, to be delivered to said first user terminal using CS signaling in said first CS network, a second IP address to be used for data transfer by said second user terminal, the second IP address to be provided from said first user terminal to said second user terminal using end-to-end IMS signaling;

receiving by said first IP access converter from said mobile switching center using CS signaling in said first CS network, a first IP address of the second user terminal, the first IP address of the second user terminal being provided from the second user terminal to the first user terminal using end-to-end IMS signaling and being provided to the mobile switching center from the first user terminal using CS signaling; and

providing data transfer;

between said first IP access converter and said mobile switching center by a CS connection in said first CS network; and

between said first IP access converter and the media gateway using the third IP address;

between said IP access converter and said second user terminal using real-time protocol, RTP; and

performing;

a) initiating a call using end-to-end IMS signaling between said first and second user terminals;

b1) initiating by said first user terminal a first CS connection in said first CS network towards said first IP access converter using CS signaling;

b2) allocating by said first IP access converter in relation to said first CS connection said second IP address to be used for data transfer by said second user terminal;

b3) establishing, by said first IP access converter, said first CS connection and providing said second IP address to said first user terminal using CS signaling;

c) providing said second IP address by said first user terminal to said second user terminal using end-to-end IMS signaling;

d) determining by said second user terminal said first IP address to be used for data transfer by said first user terminal;

e) providing said first IP address by said second user terminal to said first user terminal using end-to-end IMS signaling; and

f) providing said first IP address by said first user terminal to said first IP access converter in said first CS network using CS signaling.

2. The method according to claim 1, wherein said step d) of determining by said second user terminal comprises the steps of:

d1) initiating by said second user terminal a second CS connection in said second CS network towards a second IP access converter using CS signaling;

d2) allocating by said second IP access converter in relation to a second CS connection said first IP address to be used for data transfer by said first user terminal; and

d3) establishing by said second IP access converter said second CS connection and providing said first IP address to said second user terminal using CS signaling, and said method further comprises the step of;

g) providing said second IP address by said second user terminal to said second IP access converter In said second CS network using CS signaling.

3. The method according to claim 1, wherein said first user terminal is a calling user terminal and said second user terminal is a called user terminal, wherein said first user terminal performs said step a) of call initiation towards said second user terminal, wherein said second user terminal performs said steps d) and e) in reply to said call initiation wherein said first user terminal performs said steps b1) and f) using CS signaling comprising said first IP address, and wherein said call Is established by said first user terminal performing said step c).

4. The method according to claim 1, wherein said first user terminal is a calling user terminal and said second user terminal is a called user terminal, wherein said first user terminal performs said steps a) and b1) such that said second IP address is established and said call is initiated by said first user terminal towards said second user terminal using end-to-end IMS signaling comprising said second IP address, and wherein said call is established by said second user terminal performing said steps d) and e).

5. The method according to claim 2, wherein said first user terminal is a calling user terminal and said second user terminal is a called user terminal, wherein said first user terminal performs said steps a), b1), b2) and b3) such that said second IP address is established and said call is initiated by said first user terminal towards said second user terminal using end-to-end IMS signaling comprising said second IP address, wherein said second user terminal performs said steps d1) and g) using CS signaling comprising said second IP address, and wherein said call is established by said second user terminal performing said step e).

6. The method according to claim 1, wherein a CS network comprises a Media GateWay (MGW) for data transfer over a CS connection with a user terminal, wherein initiating a CS connection by said user terminal towards an IP access converter comprises providing a further IP address to said IP access converter by said MGW, said further IP address being associated with said CS connection for data transfer by said IP access converter with said user terminal.

7. An Internet Protocol (IP) access converter for supporting data transfer in a first Circuit Switched (CS) network and in an IP network for data transfer between a first user terminal, arranged for supporting connections in said first CS network and for simultaneously supporting Internet protocol Multi media System (IMS) signaling and CS signaling, and a second user terminal, arranged for supporting sessions and IMS signaling in an IMS, said IP access converter being arranged for:

receiving from a media gateway a third IP address at the IP access converter;

delivering to said first user terminal using CS signaling in said first CS network a second IP address to be used for data transfer by said second user terminal;

receiving from said first user terminal using CS signaling in said first CS network a first IP address for data transfer by said first user terminal, and

providing data transfer;

with said first user terminal by a CS connection in said first CS network and with said second user terminal by said IP network using said first IP address; and

with said media gateway using time division multiplex signaling and using said third IP address

performing;

a) initiating a call using end-to-end IMS signaling between said first and second user terminals;

b1) initiating by said first user terminal a first CS connection in said first CS network towards said first IP access converter using CS signaling;

b2) allocating by said first IP access converter in relation to said first CS connection said second IP address to be used for data transfer by said second user terminal;

b3) establishing, by said first IP access converter, said first CS connection and providing said second IP address to said first user terminal using CS signaling;

c) providing said second IP address by said first user terminal to said second user terminal using end-to-end IMS signaling;

d) determining by said second user terminal said first IP address to be used for data transfer by said first user terminal;

e) providing said first IP address by said second user terminal to said first user terminal using end-to-end IMS signaling; and

f) providing said first IP address by said first user terminal to said first IP access converter in said first CS network using CS signaling.

8. The IP access converter according to claim 7, wherein said IP access converter in the course of a call initiation using end-to-end IMS signaling between said first and second user terminals is further arranged for:

allocating in relation to said CS connection said second IP address to be used for data transfer by said second user terminal; and

establishing said CS connection.