Methods and apparatus for improving a call fallback user experience

Patent metadata

Field	Value
Publication number	US-9578554-B2
Application number	US-201213620135-A
Country	US
Kind code	B2
Filing date	Sep 14, 2012
Priority date	Sep 21, 2011
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Certain aspects of the present disclosure relate to techniques for improving a circuit-switched fallback (CSFB) user experience. In aspects, methods and systems for autonomously returning a user equipment (UE) from a 2G (2 nd generation)/3G (3 rd generation) network to an LTE (Long Term Evolution) network are provided. The UE may store a flag to note whether a current circuit switched (CS) call in the 2G/3G network is a result of a CSFB. The UE, in response to detecting a termination of the current CS call in the 2G/3G network and determining that the terminated call was a CSFB call (e.g., from the status of the flag), may trigger a mobility mechanism to autonomously return the UE to the LTE network.

First claim

What is claimed is:

1. A method for wireless communications, comprising:
receiving at a user equipment (UE), an indication that a call in a first radio access network (RAN) has ended;
detecting that a PLMN (Public Land Mobile Network) serving the UE is included in a list of PLMNs maintained by the UE;
in response to the detecting:
determining that the UE left service in a second RAN to establish the call in the first RAN; and
in response to the receiving and the determination, taking one or more actions by the UE to autonomously return to the second RAN, wherein a combination of detecting that the call in the first RAN has ended and that the UE left service in the second RAN to establish the call in the first RAN triggers the one or more actions by the UE,
wherein taking the one or more actions comprises sending a request to the first RAN to release a connection with the UE.

2. The method of claim 1 , wherein taking the one or more actions further comprises:
performing a cell selection procedure to select a cell of the second RAN; and
connecting by the UE to the selected cell of the second RAN.

3. The method of claim 2 , wherein taking the one or more actions further comprises:
receiving an acknowledgement of the request from the first RAN; and
wherein performing the cell selection procedure includes performing the cell selection procedure in response to receiving the acknowledgement of the request from the first RAN.

4. The method of claim 2 , wherein taking the one or more actions further comprises:
receiving an indication from the first RAN that the connection with the UE has been released; and
wherein performing the cell selection procedure includes performing the cell selection procedure in response to receiving the indication from the first RAN that the connection with the UE has been released.

5. The method of claim 2 , wherein taking the one or more actions further comprises:
determining a configurable timer has expired; and
wherein performing the cell selection procedure includes performing the cell selection procedure in response to expiration of the configurable timer.

6. The method of claim 5 wherein the configurable timer is started when the request is sent to the first RAN to release a connection with the UE.

7. The method of claim 2 , wherein the request to the first RAN to release the connection with the UE includes a Signaling Connection Release Indication (SCRI) message.

8. The method of claim 1 , wherein the first RAN comprises at least one of a second generation (2G) RAN or a third generation (3G) RAN.

9. The method of claim 1 , wherein the second RAN comprises a Long-Term Evolution RAN.

10. The method of claim 1 , wherein taking the one or more actions comprises:
performing a cell selection procedure to select a cell that supports the second RAN; and
connecting by the UE to the selected cell of the second RAN.

11. The method of claim 1 , wherein determining that the UE left service in the second RAN to take the call in the first RAN includes determining that a circuit switched fall back indicator bit is set on the UE.

12. The method of claim 1 , wherein the indication that the call in the first radio access network (RAN) has ended includes a radio bearer release message.

13. The method of claim 1 , wherein the call is a circuit switched call.

14. An apparatus for wireless communications, comprising:
means for receiving at a UE an indication that a call in a first radio access network (RAN) has ended;
means for detecting that a PLMN (Public Land Mobile Network) serving the UE is included in a list of PLMNs maintained by the UE; and
means for, in response to the detecting,
determining that the UE left service in a second RAN to establish the call in the first RAN, and
taking one or more actions by the UE to autonomously return to the second RAN, in response to the receiving and the determination, wherein a combination of detecting that the call in the first RAN has ended and that the UE left service in the second RAN to establish the call in the first RAN triggers the one or more actions by the UE,
wherein taking the one or more actions comprises sending a request to the first RAN to release a connection with the UE.

15. The apparatus of claim 14 , wherein the means for taking the one or more actions further comprise:
means for performing a cell selection procedure to select a cell of the second RAN; and
means for connecting by the UE to the selected cell of the second RAN.

16. The apparatus of claim 15 , wherein the means for taking the one or more actions further comprise:
means for receiving an acknowledgement of the request from the first RAN; and
wherein the means for performing the cell selection procedure includes means for performing the cell selection procedure in response to receiving the acknowledgement of the request from the first RAN.

17. The apparatus of claim 15 , wherein the means for taking the one or more actions further comprise:
means for receiving an indication from the first RAN that the connection with the UE has been released; and
wherein the means for performing the cell selection procedure includes means for performing the cell selection procedure in response to receiving the indication from the first RAN that the connection with the UE has been released.

18. The apparatus of claim 15 , wherein the means for taking the one or more actions further comprise:
means for determining a configurable timer has expired; and
wherein the means for performing the cell selection procedure includes means for performing the cell selection procedure in response to expiration of the configurable timer.

19. The apparatus of claim 18 wherein the configurable timer is started when the request is sent to the first RAN to release a connection with the UE.

20. The apparatus of claim 15 , wherein the request to the first RAN to release the connection with the UE includes a Signaling Connection Release Indication (SCRI) message.

21. The apparatus of claim 14 , wherein the first RAN comprises at least one of a second generation (2G) RAN or a third generation (3G) RAN.

22. The apparatus of claim 14 , wherein the second RAN comprises a Long-Term Evolution RAN.

23. The apparatus of claim 14 , wherein the means for taking the one or more actions comprise:
means for performing a cell selection procedure to select a cell that supports the second RAN; and
means for connecting by the UE to the selected cell of the second RAN.

24. The apparatus of claim 14 , wherein the means for determining that the UE left service in the second RAN to establish the call in the first RAN includes means for determining that a circuit switched fall back indicator bit is set on the UE.

25. The apparatus of claim 14 , wherein the indication that the call in the first radio access network (RAN) has ended includes a radio bearer release message.

26. The apparatus of claim 14 , wherein the call is a circuit switched call.

27. A apparatus for wireless communications, comprising:
at least one processor configured to:
receive at a UE an indication that a call in a first radio access network (RAN) has ended;
detect that a PLMN (Public Land Mobile Network) serving the UE is included in a list of PLMNs maintained by the UE;
wherein the at least one processor, based on the detection, is configured to:
determine that the UE left servic

Assignees

• Umatt Bhupesh Manoharlal
• Mandadapu Krishna Rao
• Vangaru Srinivasa Prasad
• Krishnamoorthy Sathish
• Bhattacharjee Supratik
• Thomas Joe
• Klingenbrunn Thomas
• Ramachandran Shyamal
• Qualcomm Inc

Inventors

• Umatt Bhupesh Manoharlal
• Mandadapu Krishna Rao
• Vangaru Srinivasa Prasad
• Krishnamoorthy Sathish
• Bhattacharjee Supratik
• Thomas Joe
• Klingenbrunn Thomas
• Ramachandran Shyamal

Classifications

• H04W8/02

  Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks · CPC title

• H04W36/00224 Primary

  between packet switched [PS] and circuit switched [CS] network technologies, e.g. circuit switched fallback [CSFB] · CPC title

• H04W36/0022 Primary

  for transferring data sessions between adjacent core network technologies · CPC title

• H04W76/30

  Connection release · CPC title