Preserving sessions in a wireless network

• US 20060294241A1
• Filed: 06/24/2005
• Published: 12/28/2006
• Est. Priority Date: 06/24/2005
• Status: Active Grant

• Current Assignee: Ericsson Evdo, Inc. (CommScope Holding Company, Inc.)
• Original Assignee: Airvana Incorporated (CommScope Holding Company, Inc.)
• Inventors: Cherian, Sanjay, Barabell, Arthur J., Ng, Dennis, Garg, Deepak, Ramaswamy, Suresh
• Granted Patent: US 8,099,504 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04W 76/20 Manipulation of established connections

Abstract

A radio network controller and methods for reestablishing sessions in a wireless network are described. At least a portion of session information associated with a first session is saved; and in response to detecting an unexpected degradation of the first session, reestablishment of the first session is triggered using the portion of the session information.

Claims

1. A method comprising:

saving at least a portion of session information associated with a first session between an access terminal and a first wireless network device;

in response to detecting an unexpected degradation of the first session, triggering a reestablishment of the first session using the portion of the session information.

2. The method of claim 1 wherein degradation comprises cessation.

3. The method of claim 1 wherein triggering a reestablishment of the first session further comprises:

transmitting to the access terminal a close session message.

4. The method of claim 1 further comprising replicating the first session without closing the first session.

5. The method of claim 1 wherein detecting a degradation of the first session comprises detecting a state of the first wireless device.

6. The method of claim 5 wherein the state comprises failure.

7. The method of claim 4 further comprising:

restoring the first session upon receiving a request to open a new session from the access terminal.

8. The method of claim 1 wherein the triggering complies with a 1×

Evolution-Data Optimized protocol.

9. The method of claim 3 wherein transmitting a close session message occurs immediately upon detection of a unexpected degradation of the first session.

10. The method of claim 3 wherein transmitting a close session message occurs after receiving a request to transmit data to the access terminal.

11. The method of claim 1 wherein the reestablishment of the first session is triggered based on a load state of a second wireless network device.

12. The method of claim 3 further comprising:

placing degraded sessions in a queue for transmitting a close session message; and

moving a queued degraded session up in the queue in response to receiving a request to transmit data to an access terminal associated with the degraded session.

13. The method of claim 12 wherein the degraded sessions comprise breached sessions.

14. The method of claim 1 wherein the access terminal comprises at least one of:

a cellular telephone, a personal data assistant, or a laptop computer.

15. The method of claim 3 further comprising deleting the session information for the session assigned to the access terminal if the access terminal has failed to request to open a new session after a predetermined time has elapsed after transmitting the close session message to the access terminal.

16. The method of claim 4 further comprising deleting the session information for the session assigned to the access terminal if a second wireless network device fails to reestablish the first session with the access terminal after a predetermined time has elapsed after sending the portion of the session information.

17. The method of claim 1 further comprising:

establishing the first session between the access terminal and a first wireless network device.

18. The method of claim 3 wherein the session information is saved on a second wireless network device.

19. The method of claim 18 wherein the close session message is generated by the second wireless network device.

20. The method of claim 19 wherein the close session message is transmitted by the second wireless network device.

21. The method of claim 20 further comprising:

establishing a second session between the access terminal and the second wireless network device; and

saving at least a portion of the second session information to a third wireless network device, wherein the portion of the second session information is sufficient to reestablish the second session between the access terminal and the third wireless network device.

22. The method of claim 20 wherein the portion of the second session information is sufficient to generate a close session message for the access terminal for the second session.

23. A method comprising reestablishing a breached session in response to receiving a close session message.

24. The method of claim 23 wherein reestablishing the breached session further comprises:

closing the breached session; and

sending a request to open a new session.

25. A radio network controller comprising:

a first radio node server module configured to establish a session with a first access terminal;

a storage device configured to store at least a portion of the session information that is sufficient to reestablish the session; and

a control mechanism configured to cause a second radio node server module device to reestablish the session with the access terminal after detecting a degradation of the session between the first radio node server module and the access terminal.

26. The radio network controller of claim 25 wherein degradation comprises termination.

27. The radio network controller of claim 25 wherein the session information is sufficient to generate a close session message and the control mechanism is further configured to transmit the close session message to the access terminal.

28. The radio network controller of claim 25 wherein the control mechanism is further configured to retrieve the portion of the session information from the storage device and send the portion to the second radio node server module without causing the session to be closed.

29. The radio network controller of claim 25 wherein the control mechanism is configured to comply with a 1×

Evolution-Data Optimized protocol.

30. The radio network controller of claim 27 wherein the second radio node server module transmits a close session message immediately after the control mechanism detects a degradation of the session between the first radio node server module and the access terminal.

31. The radio network controller of claim 30 wherein degradation comprises cessation.

32. The radio network controller of claim 27 wherein the second radio node server module transmits a close session message only after the control mechanism receives a request to transmit data to the access terminal.

33. The radio network controller of claim 27 further comprising a queue for transmitting a close session message wherein degraded sessions are placed, the queue moving a closed session to a higher entry in response to receiving a request to transmit data to an access terminal associated with at least one of the degraded sessions.

34. The radio network controller of claim 33 wherein the degraded sessions comprise breached sessions.

35. The radio network controller of claim 25 wherein the first radio node server module comprises a first processing card and the second radio node server module comprises a second processing card.

36. The radio network controller of claim 25 wherein the storage device comprises at least one of a non-volatile random access memory, a flash memory, and a disk memory.

37. The radio network controller of claim 25 wherein the control mechanism is implemented on a processor, the processor connecting to the first radio node server module and the second radio node server module through a high speed bus.

38. The radio network controller of claim 27 wherein the control mechanism is implemented on the second radio node server module.

39. The radio network controller of claim 27 wherein the control mechanism is implemented on a third radio node server module.

40. The radio network controller of claim 28 wherein the control mechanism is implemented on the second radio node server module.

41. The radio network controller of claim 28 wherein the control mechanism is implemented on a third radio node server module.

42. A method for reestablishing breached sessions in a wireless communications network, the method comprising:

placing a first session that has been breached in a queue for reestablishment of the first session;

placing a second session that has been breached in the queue for reestablishment of the second session, wherein the second session is prioritized below the first session in the queue; and

promoting the second session above the first session in the queue in response to receiving a request to transmit data to an access terminal associated with the second session.

43. The method of claim 42 wherein the wireless communications network uses a 1×

Evolution-Data Optimized protocol.

44. The method of claim 42 further comprising triggering a reestablishment of the second session.

45. The method of claim 44 wherein triggering a reestablishment comprises generating and transmitting a close session message to the access terminal associated with the second session.

46. The method of claim 42 further comprising reestablishing the second session between a wireless network device and the access terminal.

47. The method of claim 45 wherein reestablishment is triggered based on a load state of a second wireless network device.

48. The method of claim 45 further comprising:

triggering reestablishment of the first session after triggering reestablishment of the second session.

49. The method of claim 45 further comprising:

triggering reestablishment of the first session after triggering reestablishment of the second session only after receiving a request to transmit data to an access terminal associated with the first session.

50. The method of claim 45 further comprising:

monitoring the time that the first session has spent in the queue; and

deleting the first session if it has occupied an entry in the queue past a predetermined time period.

51. A computer readable medium having instructions stored thereon, that, when executed by a processor, cause the processor to:

save information associated with a first session with a wireless access terminal on a wireless network; and

;

in response to detecting an unexpected degradation of the first session, triggering a reestablishment of the first session using the saved information.

52. The computer-readable medium of claim 51 wherein triggering a reestablishment comprises transmitting a close session message to the access terminal, the close session message instructing the access terminal to open a new session.

53. The computer-readable medium of claim 51 having further instructions that cause the processor to restore the first session upon receiving a request to open a new session from the access terminal.

54. The computer-readable medium of claim 51 having further instructions that cause the processor to replicate the first session without closing the first session.

55. The computer-readable medium of claim 51 wherein the wireless network uses the 1×

Evolution-Data Optimized protocol.

56. The computer-readable medium of claim 51 wherein the reestablishment of the first session is triggered based on a load.

57. The computer-readable medium of claim 51 further causing the processor to prioritize closed network sessions in a wireless communications network, the processor being caused to:

place a first session that has been breached in a queue for reestablishment of the first session;

place a second session that has been breached in the queue for reestablishment of the second session, wherein the second session is prioritized below the first session in the queue; and

promote the second session above the first session in the queue in response to receiving a request to transmit data to an access terminal associated with the second session.

58. The method of claim 57 further comprising:

triggering reestablishment of the first session after triggering reestablishment of the second session.

59. The method of claim 57 further comprising:

triggering reestablishment of the first session after triggering reestablishment of the second session only after receiving a request to transmit data to an access terminal associated with the first session.