Call Clearing for legacy mobile circuit switched domain wireless systems

• US 20030169729A1
• Filed: 12/20/2002
• Published: 09/11/2003
• Est. Priority Date: 03/08/2002
• Status: Active Grant

• Current Assignee: Blackberry Limited
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Bienn, Marvin, Bharatia, Jayshree A., Pendleton, Amy
• Granted Patent: US 7,436,817 B2
• Time in Patent Office: Days
• US Class Current: 370/353
• CPC Class Codes: H04L 12/4633 Interconnection of networks using encapsulation techniques, e.g. tunneling
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A telecommunications system having a first PS network, second PS network and a third circuit-switched core network includes a system for terminating a legacy domain circuit-switched communication upon receipt of a trigger signal requesting termination of communication. The system includes first and second functional entities in each network. The first and second functional entities of the first network can communicate signals over an interface using a PS protocol. The first and second functional entities of the second network include can communicate signals over an interface using a PS protocol. The first functional entity of the first network can communicate packet data to and from the first functional entity of the second network. The second functional entity of the first network communicates a PS protocol signal to the second entity of the second network, which then communicates a circuit-switched protocol signal to and from the third circuit-switched protocol core network to terminate the circuit-switched communication.

Claims

1. An interworking engine operable in a first PS network for clearing a call between a second PS network and a CS network, comprising:

a first input employable to receive a first CS protocol signal from the CS network to trigger initiation of a call clearing action;

a mapper employable to map the first CS protocol signal into a first PS protocol signal relating to clearing a call;

a first output employable to transmit the first PS protocol signal relating to clearing the call to an interworking engine of the second PS network;

a second output employable to transmit a second PS protocol signal, in device control format, to a media gateway requesting subtraction of a trunk line and subtraction of an RTP;

a second input employable to receive a first PS protocol response from the interworking engine of the second PS network to the first PS protocol signal;

a third input employable to receive a second PS protocol response from the media gateway, in device control format, to the second PS protocol signal;

a mapper employable to map a PS protocol message relating to clearing the call into a CS protocol format; and

a third output employable to transmit a second CS protocol message to the CS network relating to clearing of the call.

2. The interworking engine of claim 1, wherein the first CS protocol signal comprises SS7 protocol.

3. The interworking engine of claim 1, wherein the first PS protocol signal comprises SIP.

4. The interworking engine of claim 1, wherein the first PS protocol response comprises SIP.

5. The interworking engine of claim 1, wherein the second PS protocol signal comprises Megaco protocol.

6. The interworking engine of claim 1, wherein the second PS protocol response comprises Megaco protocol.

7. The interworking engine of claim 1, wherein the second CS protocol message response comprises SS7 protocol.

8. A media gateway in a first PS network functioning as a bearer for communications between it and a second PS network and between it and a CS network, comprising:

a first interface employable to receive a PS protocol signal, in device control format, from an interworking engine of the first PS network requesting subtraction of a trunk line and subtraction of an RTP; and

a second interface employable to transmit a PS protocol response to the PS protocol signal from the interworking engine of the first PS network.

9. The media gateway of claim 8, wherein the PS protocol signal comprises Megaco protocol.

10. The media gateway of claim 8, wherein the PS protocol response comprises Megaco protocol.

11. The media gateway of claim 9, wherein the PS protocol comprises a Megaco subtract trunk command and a subtract RTP command.

12. The media gateway of claim 10, wherein the PS protocol response comprises a Megaco Reply.

13. A telecommunications system having at least a first PS network and a second PS network and a third circuit-switched core network, and a system for terminating a legacy domain circuit-switched communication upon receipt of a trigger signal requesting termination of communication, the system for terminating a legacy domain circuit-switched communication, comprising:

a first functional and a second functional entity in each of said first and second networks;

said first functional entity and said second functional entity of said first network including means for communicating signals over an interface using a PS protocol;

said first functional entity and said second functional entity of said second network including means for communicating signals over an interface using a PS protocol;

said first functional entity of said first network having means for communicating packet data to and from said first functional entity of the second network;

said second functional entity of said first network having means for communicating a PS protocol signal to said second entity of said second network; and

said second functional entity of said second network further including means for communicating a circuit-switched protocol signal to and from said third circuit-switched protocol core network to terminate said circuit-switched communication.

14. The system defined in claim 13, wherein said second functional entity of said first network includes means for communicating signals to and from a public switched telephone network using a circuit-switched protocol.

15. The system defined in claim 13, wherein said first functional entity is a mobile gateway.

16. The system defined in claim 13, wherein said second functional entity is a mobile switching center emulator.

17. The system defined in claim 13, wherein said second network entity of each of said first and second networks includes means for receiving a trigger signal requesting termination of a circuit-switched communication.

18. The system defined in claim 17, wherein said trigger signal is a clear signal from an access network.

19. The system defined in claim 17, wherein said trigger signal is a service release signal.

20. The system defined in claim 13, wherein said means for said second network entity of said first network to communicating signals to and from said second network entity of said second network includes a Megaco subtract trunk signal and a subtract RTP signal.

21. The system defined in claim 13, wherein said means for said second network entity of said first network to communicating signals to and from said second network entity of said second network includes a Megaco reply signal.

22. The system defined in claim 13, wherein said means for communicating signals to and from said third circuit-switched protocol network uses an open-standards circuit-switched communications protocol.

23. The system defined in claim 22, wherein said open-standards circuit-switched communications protocol includes an SS7 REL signal.

24. The system defined in claim 22, wherein said open-standards circuit-switched communications protocol includes an SS7 RLC signal.

25. The system defined in claim 13, wherein said means for said second functional entity and of said first network to communicate signals to and from said second functional entity of said second network comprises an SIP BYE signal.

26. The system defined in claim 13, wherein said means for said second functional entity and of said first network to communicate signals to and from said second functional entity of said second network comprises an SIP OK signal.

36. The system defined in claim 13, where said communicating of signals to and from said third circuit-switched protocol network is performed using an open-standards circuit-switched communications protocol.

37. The system defined in claim 25, wherein said open-standards circuit-switched communications protocol includes an SS7 REL signal.

38. The system defined in claim 36, wherein said open-standards circuit-switched communications protocol includes an SS7 RLC signal.

39. The system defined in claim 13, wherein said signal transmitted between said second functional entity of said first network to and from said second functional entity of said second network comprises an SIP BYE signal.

40. The system defined in claim 13, wherein said signal transmitted from said second functional entity of said first network to said second functional entity of said second network comprises an SIP OK signal.

27. In a telecommunications system having at least a first PS network and a second PS network and a third circuit-switched core network, each of said first and second networks having first and second functional entities, a method for terminating a legacy domain circuit-switched communication upon receipt of a trigger signal requesting termination of communication, comprising the steps:

communicating a PS protocol signal between said first functional entity and said second functional entity of said first network over an interface;

communicating a PS protocol signal from said second functional entity to said first functional entity of said first network over an interface to control termination of communication of packet data by said first functional entity of said first network;

communicating a PS protocol signal from said first functional entity of said first network to said first functional entity of said second network requesting termination of the communication of packet data by said first functional entity of said second network;

communicating a PS protocol signal from said second functional entity to said second functional entity of said first network over an interface to control termination of communication of packet data by said first functional entity of said second network; and

communicating a circuit-switched protocol signal from said first functional entity of said second network to said third circuit-switched protocol core network to terminate communication with said third network.

28. The method system defined in claim 27, wherein said third network is a public switched telephone network.

29. The system defined in claim 27, wherein said first functional entity is a mobile gateway.

30. The system defined in claim 27, wherein said second functional entity is a mobile switching center emulator.

31. The system defined in claim 27, wherein said second functional entity of said first network transmits a signal to the second functional entity network entity of said second network in response to receiving a trigger signal requesting termination of a circuit-switched communication.

32. The system defined in claim 31, wherein said trigger signal includes a clear signal.

33. The system defined in claim 31, wherein said trigger signal includes a service release signal.

34. The system defined in claim 27, wherein said signals transmitted from said second network entity of said first network to said second network entity of said second network include a Megaco subtract trunk signal and a subtract RTP signal.

35. The system defined in claim 27, wherein said signals transmitted from second network entity of said first network to said second network entity of said second network include a reply signal.