Processing of calls terminating in a packet switched protocol based cellular communication network

• US 6,791,988 B1
• Filed: 04/27/2000
• Issued: 09/14/2004
• Est. Priority Date: 04/29/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hundscheidt, Frank, Hameleers, Heino, Valentine, Eric, Terill, Stephen, Odling, Helena
• Primary Examiner(s): Pezzlo, John
• Application Number:
  US09/560,242
• Time in Patent Office: 1,601 Days
• Field of Search: 370/352-356, 370/400, 370/401, 370/466, 370/467, 370/329, 370/252
• US Class Current: 370/401
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

The present invention relates to a method for processing a call within a communication network having a packet switched protocol based cellular telephone network comprising a first layer for transferring signalling information assigned to a telephone call being processed by the communication network, a second layer for transferring payload information assigned to the telephone call and interface means for coupling the cellular telephone network to a further network the interface means comprising payload information exchange function between the cellular telephone network and the further network, wherein the second layer of the cellular telephone network transfers the payload information of the telephone call to and from the interface means on a direct route assigned to the telephone call within the second layer

Claims

1. A communication network having a packet switched protocol based cellular telephone network comprising a first layer for transferring signalling information assigned to a telephone call being processed by the communication network, a second layer for transferring payload information assigned to the telephone call and interface means for coupling the cellular telephone network to a further network, the interface means comprising signalling information exchange function between the cellular telephone network and the further network and payload information exchange function between the cellular telephone network and the further network, the first layer and the second layer of the cellular telephone network being coupled to the interface means, wherein the second layer of the cellular telephone network transfers the payload information of the telephone call to and from the interface means on a direct route assigned to the telephone call within the second layer and the first layer of the cellular telephone network comprises controlling means for controlling the routing of the telephone call initiated from the further network and terminating in the packet switched protocol based cellular telephone network.

2. The communication network of claim 1, wherein the controlling means for routing the telephone call comprises a gateway mobile services switching center (GMSC) and a home location register (HLR) being coupled via a HLR/GMSC signalling connection to the GMSC.

3. The communication network of claim 2, wherein the GMSC comprises a packet switched protocol based GMSC and the home location register comprises a packet switched protocol based home location register, both being operated on the basis of a packet switched protocol.

4. The communication network of claim 3, wherein the interface means comprises a signalling gateway (SGW) that is coupled to the further network via a signalling connection and to the GMSC via a GMSC/SGW signalling connection.

5. The communication network of claim 3, wherein the interface means comprises a media gateway (MGW) that is coupled to the further network via a payload connection for transferring payload information of a call from the further network to the media gateway and vice versa.

6. The communication network of claim 5, wherein the GMSC is coupled to the media gateway via a GMSC/MGW signalling connection.

7. The communication network of claim 6, wherein the packet switched protocol based cellular telephone network comprises at least one circuit switched protocol based mobile services switching center, at least one circuit switched protocol based base station controller coupled to the mobile services switching center and at least one circuit switched protocol based base transceiver station coupled to the base station controller.

8. The communication network of claim 7, wherein the packet switched protocol based cellular telephone network comprises at least one circuit switched protocol based visitor location register being coupled to the mobile services switching center.

9. The communication network of claim 7, wherein the packet switched protocol based cellular telephone network comprises a further media gateway being coupled to the mobile services switching center via a MSC/MGW payload connection for transferring payload information of the call from the mobile services switching center to the further media gateway and vice versa, the further media gateway being coupled to the other, second media gateway via a MGW/MGW payload connection for transferring payload information of the call between both of the media gateways, and the further media gateway being coupled to the GMSC via a further GMSC/MGW signalling connection.

10. The communication network of claim 7, wherein the mobile services switching center is coupled to the GMSC via a further signalling gateway.

11. The communication network of claim 10, wherein the home location register is coupled to the further signalling gateway.

12. The communication network of claim 6, wherein the packet switched protocol based cellular telephone network comprises at least one packet switched protocol based mobile services switching center, at least one packet switched protocol based base station controller coupled to the mobile services switching center and at least one packet switched protocol based base transceiver station coupled to the base station controller.

13. The communication network of claim 12, wherein the packet switched protocol based cellular telephone network comprises at least one packet switched protocol based visitor location register being coupled to the mobile services switching center.

14. The communication network of claim 12, wherein the mobile services switching center is coupled to the GMSC via a MSC/GMSC signalling connection.

15. The communication network of claim 14, wherein the home location register is coupled to the visitor location register via a signalling connection.

16. The communication network of claim 15, wherein the mobile services switching center is coupled to the media gateway via a MSC/MGW signalling connection.

17. The communication network of claim 12, wherein the base transceiver station is coupled to the media gateway via a direct payload connection for transferring payload information of the call therebetween.

18. The communication network of claim 2, wherein the GMSC comprises a circuit switched protocol based GMSC and the home location register comprises a circuit switched protocol based home location register, both being operated on the basis of a circuit switched protocol.

19. The communication network of claim 18, wherein the GMSC is coupled to the further network via a signalling connection and via a payload connection.

20. The communication network of claim 18, wherein the second layer of the packet switched protocol based cellular telephone network comprises a media gateway (MGW) that is coupled to the GMSC via a GMSC/MGW payload connection for transferring payload information of a call from the GMSC to the media gateway and vice versa.

21. The communication network of claim 20, wherein the packet switched protocol based cellular telephone network comprises at least one packet switched protocol based mobile services switching center, at least one packet switched protocol based base station controller coupled to the mobile services switching center and at least one packet switched protocol based base transceiver station coupled to the base station controller.

22. The communication network of claim 21, wherein the packet switched protocol based cellular telephone network comprises at least one packet switched protocol based visitor location register being coupled to the mobile services switching center.

23. The communication network of claim 21, wherein the mobile services switching center is coupled to the GMSC via a signalling gateway of the first layer.

24. The communication network of claim 23, wherein the home location register is coupled to the signalling gateway.

25. The communication network of claim 21, wherein the mobile services switching center is coupled to the media gateway via a MSC/MGW signalling connection.

26. The communication network of claim 21, wherein the base transceiver station is coupled to the media gateway via a direct payload connection for transferring payload information of the call therebetween.

27. The communication network of claim 1, wherein the cellular telephone network part comprises a GSM network.

28. The communication network of claim 1, wherein the further network comprises a general switched telephone network (GSTN), the GSTN comprising at least one of a packet switched network and a circuit switched network.

29. The communication network of claim 28, wherein the packet switched network comprises at least one of the Internet, a VoIP network, an Internet Protocol network, a GPRS network, and a UMTS network.

30. The communication network of claim 28, wherein the circuit switched network comprises at least one of a ISDN network, a PLMN network, and a PSTN network.

31. The communication network of one of claim 5, wherein the media gateway comprises at least one transcoder, at least one speech transcoder, and at least one of at least one modem and at least one network access server.

32. A method for processing a telephone call in a packet switched protocol based communication network comprising a further network and a packet switched protocol based cellular telephone network having a first layer for transferring signalling Information assigned to the telephone call being processed by the communication network, a second layer for transferring payload information assigned to the telephone call, and interface means for coupling the cellular telephone network to the further network, the interface means comprising a signalling information exchange function and a payload information exchange function between the cellular telephone network and the further network, the first layer and the second layer of the cellular telephone network being coupled to the interface means, the method comprising:

initiating a call by the further network, forwarding an initial address message assigned to the call from the further network to the cellular telephone network;

after receiving the initial address message, providing routing information by the cellular telephone network on the basis of the initial address message in order to route the call to a terminating mobile station of the cellular telephone network and establishing a through-connection for transferring payload information assigned to the call within the packet switched protocol based cellular telephone network from the terminating mobile station via the second layer and the Interface means to the further network and/or vice versa.

33. The method of claim 32, wherein the cellular telephone network comprises a gateway mobile services switching center (GMSC), a home location register being coupled to the GMSC, at least one visitor location register and at least one mobile services switching center coupled to the terminating mobile station, wherein the step for providing the routing information comprises:

the GMSC interrogating the home location register for the routing information;

the home location register requesting a roaming number from the visitor location register;

the visitor location register providing the roaming number to the home location register; and

the home location register providing the routing information, including the roaming number, to the GMSC in order to determine the routing to a mobile services switching center coupled to the terminating mobile station.

34. The method of claim 33, further comprising, after receiving the routing information, determining a new signalling information field or value by the GMSC, the new signalling information field or value identifying a signalling connection between the GMSC and the mobile services switching center, including the new signalling information field or value and the signalling information field that the GMSC has received from the further network into the initial address message by the GMSC, and forwarding the initial address message to the mobile services switching center by the GMSC on the basis of the received routing information.

35. The method of claim 33, wherein the cellular telephone network comprises at least one base station controller coupled to the mobile services switching center and at least one base transceiver station coupled to the base station controller and to the terminating mobile station, wherein the method further comprises:

forwarding a request for paging the mobile station from the mobile services switching center to the base station controller; and

after having paged the mobile station, returning the result from the base station controller to the mobile services switching center.

36. The method of claim 35, further comprising:

creating a network unique call identification assigned to the telephone call in the mobile services switching center; and

forwarding the call identification to the base station controller.

37. The method of claim 36, wherein, after receiving the call identification, the base transceiver station maps the call identification into a BSC-BTS internal connection identification, provides a BTS address Identifying the base transceiver station, and forwards the BSC-BTS internal connection identification and the BTS address to the base station controller.

38. The method of claim 37, wherein the base station controller stores the BSC-BTS internal connection identification;

and forwarding the BTS address from the base station controller to the mobile services switching center.

39. The method of claim 38, wherein, after receiving the BTS address, the mobile services switching center forwards a create connection request comprising the BTS address, a bearer capability, a selected signalling information field, and the call identification to a media gateway of the interface means.

40. The method of claim 39, wherein after receiving the create connection request, the media gateway (MGW) maps the call identification into a MGW-MSC internal connection identification, provides a MGW address identifying the media gateway, and forwards a create connection complete message comprising the MGW address and the MGW-MSC internal connection identification to the mobile services switching center.

41. The method of claim 40, wherein the mobile services switching center forwards the MGW address received from the media gateway to the base transceiver station via the base station controller.

42. The method of claim 41, wherein the mobile services switching center forwards an address complete message comprising a through-connection indicator that indicates a backward through-connection to the GMSC in order to establish a backward through-connection from the media gateway to the further network.

43. The method of claim 42, wherein the mobile services switching center requests a both-way through-connection from the media gateway in order to establish the both-way through-connection between the terminating mobile station and the further network.

44. The method of claim 32, further comprising:

creating a network unique call identification assigned to the telephone call in the gateway mobile services switching center (GMSC); and

forwarding the call identification to a first media gateway.

45. The method of claim 44, wherein, after receiving the call identification, the first media gateway (MGW) maps the call identification into a GMSC-MGW internal connection identification, provides a MGW address identifying the first media gateway, and forwards the GMSC-MGW internal connection identification and the MGW address to the GMSC.

46. The method of claim 45, wherein, after receiving the MGW address of the first media gateway, the GMSC forwards a create connection request comprising the MGW address of the first media gateway, a through-connection indicator that indicates a backward through-connection, a bearer capability, a selected signalling information field and the call identification to a second media gateway of the interface means.

47. The method of claim 46, wherein, after receiving the create connection request, the second media gateway (MGW) maps the call identification into a further GMSC-MGW internal connection identification, provides a further MGW address identifying the second media gateway and forwards a create connection complete message comprising the further MGW address and the further GMSC-MGW internal connection Identification to the GMSC.

48. The method of claim 47, wherein the GMSC forwards the further MGW address received from the second media gateway to the first media gateway.

49. The method of claim 32, comprising:

forwarding the initial address message from the GSTN via a signalling gateway converting a signalling bearer and a GMSC to a mobile services switching center of the cellular telephone network;

forwarding an address complete message from the mobile services switching center via the GMSC and the signalling gateway converting the signalling bearer to the further network; and

forwarding an answer message of the mobile station from the mobile services switching center via the GMSC and the signalling gateway converting the signalling bearer to the further network.

50. The method of claim 32, comprising;

forwarding the initial address message from the further network via the GMSC of the interface means and a signalling gateway converting a signalling bearer to a mobile services switching center of the cellular telephone network;

forwarding an address complete message from the mobile services switching center via the signalling gateway converting the signalling bearer and the GMSC to the further network; and

forwarding an answer message of the mobile station from the mobile services switching center via the signalling gateway converting the signalling bearer and the GMSC to the further network.

51. The method of claim 32, comprising the following steps:

forwarding the initial address message from the further network via a second signalling gateway converting the signalling bearer, the GMSC and a first signalling gateway converting the signalling bearer to a mobile services switching center of the cellular telephone network;

forwarding an address complete message from the mobile services switching center via the first signalling gateway converting the signalling bearer, the GMSC and the second signalling gateway to the further network; and

forwarding an answer message of the mobile station from the mobile services switching center via the first signalling gateway converting the signalling bearer, the GMSC and the second signaling gateway converting the signalling bearer to the further network.