Support of voice call continuity (VCC) for wireless emergency calls

• US 20100124897A1
• Filed: 12/30/2008
• Published: 05/20/2010
• Est. Priority Date: 01/04/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Edge, Stephen W.
• Granted Patent: US 8,340,627 B2
• Time in Patent Office: Days
• US Class Current: 455/404.100
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1095 Inter-network session transfer or sharing
• CPC Class Codes: H04L 65/40 Support for services or applications
• CPC Class Codes: H04M 2242/04 for emergency applications
• CPC Class Codes: H04M 7/123 where the packet-switched network is an Internet Protocol Multimedia System-type network
• CPC Class Codes: H04M 7/1235 where one of the core networks is a wireless network
• CPC Class Codes: H04W 36/0022 for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/00226 wherein the core network technologies comprise IP multimedia system [IMS], e.g. single radio voice call continuity [SRVCC]
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 76/50 for emergency connections
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Apparatus and methods to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment are operable to receive, at a serving domain, a message containing emergency and domain transfer information from a user equipment (UE). The apparatus and methods are further operable to determine a need for emergency call origination or domain transfer based on the emergency and domain transfer information. Additionally, the apparatus and methods are operable to perform the emergency call origination or the domain transfer based on the determining.

Claims

1. A method to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment, comprising:

receiving, at a serving domain, a message containing emergency and domain transfer information from a user equipment (UE);

determining a need for emergency call origination or domain transfer based on the emergency and domain transfer information; and

performing the emergency call origination or the domain transfer based on the determining.

2. The method of claim 1, wherein the emergency and domain transfer information comprises a modified VDN.

3. The method of claim 1, wherein the emergency and domain transfer information comprises a modified VDI.

4. The method of claim 1, wherein the message is a 3GPP DTAP Emergency SETUP message and the emergency and domain transfer information comprise spare bits in an optional Service Category parameter.

5. The method of claim 2, wherein the message is a 3GPP DTAP SETUP message and the modified VDN is an E.164 number in the Called Party Number parameter.

6. The method of claim 3, wherein the message is a SIP INVITE and the modified VDI is a SIP URI.

7. The method of claim 1, wherein the serving domain is a circuit-switched (CS) serving domain.

8. The method of claim 1, wherein the serving domain is a packet-switched (PS) serving domain.

9. The method of claim 7, further comprising receiving the message in a serving MSC in the serving domain, wherein the serving MSC sends a query to a GMLC in the serving domain, wherein the query includes an emergency call origination request or a domain transfer request, wherein the GMLC returns routing information to the serving MSC based on the emergency call origination or the domain transfer request.

10. The method of claim 9, wherein the GMLC possesses two SCCP E.164 addresses, wherein the serving MSC sends the query to one address if the emergency and domain transfer information indicates an emergency call origination and to the other address if the emergency and domain transfer information indicates a domain transfer, wherein the one address indicates the emergency call origination and the other address indicates the domain transfer request.

11. The method of claim 10, wherein the GMLC determines the routing information based on which SCCP address the query was sent to.

12. The method of claim 11, wherein the routing information comprises an ESRD or an ESRK.

13. The method of claim 12, wherein the sending of the query to the GMLC and the receipt of the routing information from the GMLC is transparent to the serving MSC.

14. The method of claim 1, wherein the emergency and domain transfer information indicates that the UE can support Voice Call Continuity (VCC).

15. The method of claim 1, wherein the performing of the emergency call origination includes anchoring the emergency call in a VCC DTF.

16. The method of claim 15, wherein the VCC DTF returns a modified VDI and a modified VDN to the UE.

17. The method of claim 16, wherein the modified VDI and the modified VDN are returned to the UE in a SIP 200 OK message.

18. The method of claim 9, wherein the query is a MAP SLR and the emergency call origination or domain transfer request is included in an optional parameter of the MAP SLR.

19. The method of claim 9, wherein the emergency call origination request or the domain transfer request indicates that the UE supports VCC.

20. The method of claim 1, wherein the performing of the domain transfer includes finding a call record for the UE in a VCC DTF.

21. The method of claim 20, further comprising returning an error message to the UE if the call record is not found.

22. The method of claim 7, further comprising including a serving cell ID or MSC identity in an ISUP Initial Address Message (IAM) used to perform the Domain Transfer.

23. The method of claim 22, wherein the serving cell ID or MSC identity is included in a Generic Digits parameter in the IAM.

24. At least one processor configured to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment, comprising:

a first module for receiving a message containing emergency and domain transfer information from a user equipment (UE);

a second module for determining a need for emergency call origination or domain transfer based on the emergency and domain transfer information; and

a third module for performing the emergency call origination or the domain transfer based on the determining.

25. A computer program product configured to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment, comprising:

a computer-readable medium, comprising;

a first set of codes operable to cause a computer to receive a message containing emergency and domain transfer information from a user equipment (UE);

a second set of codes operable to cause the computer to determine a need for emergency call origination or domain transfer based on the emergency and domain transfer information; and

a third set of codes operable to cause the computer to perform the emergency call origination or the domain transfer based on the determining.

26. An apparatus configured to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment, comprising:

means for receiving a message containing emergency and domain transfer information from a user equipment (UE);

means for determining a need for emergency call origination or domain transfer based on the emergency and domain transfer information; and

means for performing the emergency call origination or the domain transfer based on the determining.

27. An apparatus to support Voice Call Continuity (VCC) for emergency calls in a wireless access environment, comprising:

at least one processor operable to execute instructions to;

receive, at a serving domain, a message containing emergency and domain transfer information from a user equipment (UE);

determine a need for emergency call origination or domain transfer based on the emergency and domain transfer information; and

perform the emergency call origination or the domain transfer based on the determining.

28. The apparatus of claim 27, wherein the emergency and domain transfer information comprises a modified VDN.

29. The apparatus of claim 27, wherein the emergency and domain transfer information comprises a modified VDI.

30. The apparatus of claim 27, wherein the message is a 3GPP DTAP Emergency SETUP message and the emergency and domain transfer information comprise spare bits in the optional Service Category parameter.

31. The apparatus of claim 28, wherein the message is a 3GPP DTAP SETUP message and the modified VDN is an E.164 number in the Called Party Number parameter.

32. The apparatus of claim 29, wherein the message is a SIP INVITE and the modified VDI is a SIP URI.

33. The apparatus of claim 27, wherein the serving domain is a circuit-switched (CS) serving domain.

34. The apparatus of claim 27, wherein the serving domain is a packet-switched (PS) serving domain.

35. The apparatus of claim 33, further comprising receiving the message in a serving MSC in the serving domain, wherein the serving MSC sends a query to a GMLC in the serving domain, wherein the query includes an emergency call origination request or a domain transfer request, wherein the GMLC returns routing information to the serving MSC based on the emergency call origination or the domain transfer request.

36. The apparatus of claim 35, wherein the GMLC possesses two SCCP E.164 addresses, wherein the serving MSC sends the query to one address if the emergency and domain transfer information indicates an emergency call origination and to the other address if the emergency and domain transfer information indicates a domain transfer, wherein the one address indicates the emergency call origination and the other address indicates the domain transfer request.

37. The apparatus of claim 36, wherein the GMLC determines the routing information based on which SCCP address the query was sent to.

38. The apparatus of claim 37, wherein the routing information comprises an ESRD or an ESRK.

39. The apparatus of claim 38, wherein the sending of the query to the GMLC and the receipt of the routing information from the GMLC is transparent to the serving MSC.

40. The apparatus of claim 27, wherein the emergency and domain transfer information indicates that the UE can support Voice Call Continuity (VCC).

41. The apparatus of claim 27, wherein the performing of the emergency call origination includes anchoring the emergency call in a VCC DTF.

42. The apparatus of claim 41, wherein the VCC DTF returns a modified VDI and a modified VDN to the UE.

43. The apparatus of claim 42, wherein the modified VDI and the modified VDN are returned to the UE in a SIP 200 OK message.

44. The apparatus of claim 35, wherein the query is a MAP SLR and the emergency call origination or domain transfer request is included in an optional parameter of the MAP SLR.

45. The apparatus of claim 35, wherein the emergency call origination request or the domain transfer request indicates that the UE supports VCC.

46. The apparatus of claim 27, wherein the performing of the domain transfer includes finding a call record for the UE in a VCC DTF.

47. The apparatus of claim 46, further comprising returning an error message to the UE if the call record is not found.

48. The apparatus of claim 33, further comprising including a serving cell ID or MSC identity in an ISUP Initial Address Message (IAM) used to perform the Domain Transfer.

49. The apparatus of claim 48, wherein the serving cell ID or MSC identity is included in a Generic Digits parameter in the IAM.