Method and apparatus for flexible call recovery in a wireless communication system

• US 7,260,401 B2
• Filed: 09/21/2001
• Issued: 08/21/2007
• Est. Priority Date: 12/05/2000
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Jun, Chen, Tao
• Primary Examiner(s): Tran; CongVan
• Application Number:
  US09/961,636
• Publication Number:
  US 20020068569A1
• Time in Patent Office: 2,160 Days
• Field of Search: 455436-439, 455/452.2, 455/450, 455/423, 455/421, 455/504, 455/522, 455/434, 455/452.1, 370/330, 370/331
• US Class Current: 455/437
• CPC Class Codes: H04W 36/24 Reselection being triggered by specific parameters
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

A method and apparatus provides for call recovery in a wireless communication system (10). When the communication link between a mobile station (38) and a base station (32) is in trouble, the mobile station and the infrastructure prearrange potential call recovery operations. A trigger often initiates a call recovery operation, wherein the trigger indicates when a parameter or metric passes a threshold. These thresholds may be dynamic, adapting to conditions of the system (10) and environment, and the thresholds may be adjusted based on a history or statistical record of operation of the system (10).

Claims

1. A method for call recovery in a wireless communication system, comprising:

detecting an occurrence of a call recovery trigger;

instructing a set of neighboring base stations to transmit on respective default channels to a mobile station;

each neighboring base station initiating transmission on a new channel with the mobile station in parallel with a transmission on the default channel; and

each neighboring base station terminating transmission on the default channel in response to a base station controller receiving a handoff complete message from the mobile station.

2. The method of claim 1, further comprising:

sending default channel assignments of the set of neighboring base stations to the mobile station.

3. The method of claim 1, further comprising:

determining an active set of base stations for the mobile station.

4. The method of claim 1, further comprising:

initiating a timer; and

transmitting a handoff direction message to initiate transmissions on the new channel in parallel with the default channel.

5. The method of claim 4, further comprising:

canceling call recovery providing that the handoff complete message from the mobile station has not been received and the timer has expired.

6. The method of claim 1, wherein the call recovery trigger occurs when the mobile station or base station receives continuous power-up requests for longer than an adjustable time period.

7. The method of claim 1, wherein the call recovery trigger occurs when a base station receives a number of erasures more than an adjustable threshold number.

8. The method of claim 1, wherein the call recovery trigger occurs when a base station receives messages indicating that its outer loop set-point is higher than an adjustable threshold for longer than an adjustable time period.

9. The method of claim 1, wherein the call recovery trigger occurs when the mobile station or base station retransmits a message for more than an adjustable threshold number when a certain response is not received.

10. The method of claim 1, wherein the call recovery trigger occurs when the base station receives a frame error rate (FER) that is higher than a threshold level for longer than a threshold time period.

11. The method of claim 1, wherein the call recovery trigger occurs when the mobile station receives errors more than an adjustable threshold level.

12. The method of claim 1, wherein the call recovery trigger occurs when the mobile station transmits at a power level higher than an adjustable threshold level for longer than an adjustable time period.

13. An apparatus for call recovery in a wireless communication system, comprising:

means for detecting an occurrence of a call recovery trigger;

means for instructing a set of neighboring base stations to transmit on respective default channels to a mobile station;

each neighboring base station including means for initiating transmission on a new channel with the mobile station in parallel with a transmission on the default channel; and

each neighboring base station including means for terminating transmission on the default channel in response to a base station controller receiving a handoff complete message from the mobile station.

14. The apparatus of claim 13, further comprising:

means for sending default channel assignments of the set of neighboring base stations to the mobile station.

15. The apparatus of claim 13, further comprising:

means for determining an active set of base stations for the mobile station.

16. The apparatus of claim 13, further comprising:

means for initiating a timer; and

means for transmitting a handoff direction message to initiate transmissions on the new channel in parallel with the default channel.

17. The apparatus of claim 16, further comprising:

means for canceling call recovery providing that the handoff complete message from the mobile station has not been received and the timer has expired.

18. The apparatus of claim 13, wherein the call recovery trigger occurs when the mobile station or base station receives continuous power-up requests for longer than an adjustable time period.

19. The apparatus of claim 13, wherein the call recovery trigger occurs when a base station receives a number of erasures more than an adjustable threshold number.

20. The apparatus of claim 13, wherein the call recovery trigger occurs when a base station receives messages indicating that its outer loop set-point is higher than an adjustable threshold for longer than an adjustable time period.

21. The apparatus of claim 13, wherein the call recovery trigger occurs when the mobile station or base station retransmits a message for more than an adjustable threshold number when a certain response is not received.

22. The apparatus of claim 13, wherein the call recovery trigger occurs when the base station receives a frame error rate (FER) that is higher than a threshold level for longer than a threshold time period.

23. The apparatus of claim 13, wherein the call recovery trigger occurs when the mobile station receives errors more than an adjustable threshold level.

24. The apparatus of claim 13, wherein the call recovery trigger occurs when the mobile station transmits at a power level higher than an adjustable threshold level for longer than an adjustable time period.