APPARATUS AND METHOD FOR AVOIDING DATA LOSS FOLLOWING AN INTER-PDSN HANDOFF BASED ON A SIMPLE IP NETWORK

• US 20160309540A1
• Filed: 01/03/2014
• Published: 10/20/2016
• Est. Priority Date: 01/03/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: ZHANG, Weiye, SONG, Haichao
• Granted Patent: US 9,872,330 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 61/4535 using an address exchange platform which sets up a session between two nodes, e.g. rendezvous servers, session initiation protocols [SIP] registrars or H.323 gatekeepers
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 61/5076 Update or notification mechanisms, e.g. DynDNS
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 76/25 Maintenance of established connections

Abstract

The disclosure is related to avoiding data loss following a handoff from a second packet data serving node (PDSN) back to a first PDSN before an expiration of a session inactivity timer at the first PDSN. An aspect includes detecting, by an access terminal, a handoff from the first PDSN to the second PDSN, in response to the detecting, starting, by the access terminal, a session keep timer corresponding to the session inactivity timer, the session inactivity timer indicating a maximum amount of time the first PDSN will maintain an inactive communication session with the access terminal, and, based on whether the session keep timer has expired, transmitting, by the access terminal, a plurality of data packets to a server until an acknowledgment is received from the server.

Claims

1. A method for avoiding data loss following a handoff from a second packet data serving node (PDSN) back to a first PDSN before an expiration of a session inactivity timer at the first PDSN, comprising:

detecting, by an access terminal, a handoff from the first PDSN to the second PDSN;

in response to the detecting, starting, by the access terminal, a session keep timer corresponding to the session inactivity timer, the session inactivity timer indicating a maximum amount of time the first PDSN will maintain an inactive communication session with the access terminal; and

based on whether the session keep timer has expired, transmitting, by the access terminal, a plurality of data packets to a server until an acknowledgment is received from the server.

2. The method of claim 1, wherein detecting the handoff from the first PDSN to the second PDSN comprises:

receiving an assignment of an Internet protocol (IP) address from the second PDSN.

3. The method of claim 1, wherein the handoff from the first PDSN to the second PDSN comprises a handoff from the first PDSN to the second PDSN while the access terminal is in a dormant state.

4. The method of claim 1, wherein the second PDSN re-synchronizes the inactive communication session in response to the handoff from the first PDSN to the second PDSN.

5. The method of claim 1, further comprising:

detecting that a parameter identifying a network entity serving the access terminal has changed.

6. The method of claim 5, wherein the session keep timer is started in response to the detecting the handoff from the first PDSN to the second PDSN and in response to detecting that the parameter identifying the network entity serving the access terminal has changed.

7. The method of claim 5, further comprising:

detecting that the parameter identifying the network entity serving the access terminal has changed again; and

in response to the detecting that the parameter has changed again, determining whether the session keep timer has expired.

8. The method of claim 1, further comprising:

in response to the transmitting, receiving an assignment of a new IP address from the first PDSN.

9. The method of claim 1, further comprising:

upon receiving the acknowledgment from the server, ceasing the transmitting and registering the new IP address with the server.

10. The method of claim 1, wherein receiving the acknowledgment from the server indicates that the first PDSN has re-synchronized the inactive communication session.

11. The method of claim 1, further comprising:

in response to receiving the acknowledgment from the server, resetting the session keep timer.

12. The method of claim 1, wherein the inactive communication session comprises a point-to-point protocol (PPP) session.

13. The method of claim 1, wherein the server comprises a voice over Internet protocol (VoIP) server.

14. The method of claim 1, wherein the plurality of data packets comprise a plurality of Internet protocol (IP) ping packets.

15. The method of claim 1, wherein the access terminal employs Simple IP.

16. An apparatus for avoiding data loss following a handoff from a second packet data serving node (PDSN) back to a first PDSN before an expiration of a session inactivity timer at the first PDSN, comprising:

logic configured to cause an access terminal to detect a handoff from the first PDSN to the second PDSN;

logic configured to cause the access terminal to start, in response to detecting the handoff, a session keep timer corresponding to the session inactivity timer, the session inactivity timer indicating a maximum amount of time the first PDSN will maintain an inactive communication session with the access terminal; and

logic configured to cause the access terminal to transmit, based on whether the session keep timer has expired, a plurality of data packets to a server until an acknowledgment is received from the server.

17. The apparatus of claim 16, wherein the logic configured to cause the access terminal to detect the handoff from the first PDSN to the second PDSN comprises:

logic configured to cause the access terminal to receive an assignment of an Internet protocol (IP) address from the second PDSN.

18. The apparatus of claim 16, wherein the handoff from the first PDSN to the second PDSN comprises a handoff from the first PDSN to the second PDSN while the access terminal is in a dormant state.

19. The apparatus of claim 16, wherein the second PDSN re-synchronizes the inactive communication session in response to the handoff from the first PDSN to the second PDSN.

20. The apparatus of claim 16, further comprising:

logic configured to cause the access terminal to detect that a parameter identifying a network entity serving the access terminal has changed.

21. The apparatus of claim 20, wherein the session keep timer is started in response to the detecting the handoff from the first PDSN to the second PDSN and in response to detecting that the parameter identifying the network entity serving the access terminal has changed.

22. The apparatus of claim 20, further comprising:

logic configured to cause the access terminal to detect that the parameter identifying the network entity serving the access terminal has changed again; and

logic configured to cause the access terminal to determine whether the session keep timer has expired in response to detecting that the parameter has changed again.

23. The apparatus of claim 16, further comprising:

logic configured to cause the access terminal to receive an assignment of a new IP address from the first PDSN in response to transmitting the plurality of data packets.

24. The apparatus of claim 16, further comprising:

logic configured to cause the access terminal to cease the transmitting and registering the new IP address with the server upon receiving the acknowledgment from the server.

25. The apparatus of claim 16, wherein receiving the acknowledgment from the server indicates that the first PDSN has re-synchronized the inactive communication session.

26. The apparatus of claim 16, further comprising:

logic configured to cause the access terminal to reset the session keep timer in response to receiving the acknowledgment from the server.

27. The apparatus of claim 16, wherein the inactive communication session comprises a point-to-point protocol (PPP) session.

28. The apparatus of claim 16, wherein the server comprises a voice over Internet protocol (VoIP) server.

29. An apparatus for avoiding data loss following a handoff from a second packet data serving node (PDSN) back to a first PDSN before an expiration of a session inactivity timer at the first PDSN, comprising:

means for causing an access terminal to detect a handoff from the first PDSN to the second PDSN;

means for causing the access terminal to start, in response to detecting the handoff, a session keep timer corresponding to the session inactivity timer, the session inactivity timer indicating a maximum amount of time the first PDSN will maintain an inactive communication session with the access terminal; and

means for causing the access terminal to transmit, based on whether the session keep timer has expired, a plurality of data packets to a server until an acknowledgment is received from the server.

30. A non-transitory computer-readable medium for avoiding data loss following a handoff from a second packet data serving node (PDSN) back to a first PDSN before an expiration of a session inactivity timer at the first PDSN, comprising:

at least one instruction to cause an access terminal to detect a handoff from the first PDSN to the second PDSN;

at least one instruction to cause the access terminal to start, in response to detecting the handoff, a session keep timer corresponding to the session inactivity timer, the session inactivity timer indicating a maximum amount of time the first PDSN will maintain an inactive communication session with the access terminal; and

at least one instruction to cause the access terminal to transmit, based on whether the session keep timer has expired, a plurality of data packets to a server until an acknowledgment is received from the server.