SYSTEMS AND METHODS FOR MULTIMODE WIRELESS COMMUNICATION HANDOFF

• US 20090280812A1
• Filed: 03/25/2009
• Published: 11/12/2009
• Est. Priority Date: 05/11/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Kuo-Chun, Chin, Tom, Shi, Guangming Carl, Cheng, Steven D.
• Granted Patent: US 9,036,599 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 36/0079 in case of hand-off failure or rejection
• CPC Class Codes: H04W 36/1443 between licensed networks
• CPC Class Codes: H04W 68/005 Transmission of information for alerting of incoming communication
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Methods and apparatus for easily and quickly returning to a first radio access technology (RAT) network when handover to a second RAT network is cancelled are provided. The methods and apparatus may involve a mobile station (MS) entering idle mode before handover to the second RAT network is completed and requesting a serving base station (BS) to retain MS service and operational information, as well as service flow state information. In this manner, should handover to the second RAT network be cancelled before completion, a re-entry to the first RAT network may be expeditiously performed using the retained MS information.

Claims

1. A method for performing handover between network service via first and second radio access technologies (RATs), comprising:

communicating via the first RAT;

triggering a handover to network service via the second RAT, wherein the first and second RATs are different; and

entering an idle mode before completing the handover to network service via the second RAT.

2. The method of claim 1, further comprising requesting network service via the first RAT to retain mobile station (MS) information before entering the idle mode.

3. The method of claim 2, wherein the MS information comprises at least one of service information, operational information, or service flow state information.

4. The method of claim 2, further comprising:

canceling the handover to network service via the second RAT before completing the handover;

receiving the retained MS information; and

performing network re-entry using the received retained MS information to restore communication via the first RAT.

5. The method of claim 1, wherein entering the idle mode comprises entering the idle mode before accessing network service via the second RAT during the handover.

6. The method of claim 1, further comprising requesting network service via the first RAT to increase a period between transmitting paging messages before entering the idle mode.

7. The method of claim 6, wherein requesting network service via the first RAT to increase the period between transmitting the paging messages comprises:

setting a Paging Cycle value in a Paging Cycle Request field of a De-Registration Request (DREG-REQ) message; and

transmitting the DREG-REQ message.

8. The method of claim 7, wherein setting the Paging Cycle value comprises:

determining a maximum time to return to network service via the first RAT and a number of paging retries for network service via the first RAT;

calculating a minimum Paging Cycle value by dividing the maximum time to return by the number of paging retries minus one; and

setting the Paging Cycle value greater than or equal to the minimum Paging Cycle value.

9. An apparatus for performing handover between network service via first and second radio access technologies (RATs), comprising:

means for communicating via the first RAT;

means for triggering a handover to network service via the second RAT, wherein the first and second RATs are different; and

means for entering an idle mode before completing the handover to network service via the second RAT.

10. The apparatus of claim 9, further comprising means for requesting network service via the first RAT to retain mobile station (MS) information before entering the idle mode.

11. The apparatus of claim 10, wherein the MS information comprises at least one of service information, operational information, or service flow state information.

12. The apparatus of claim 10, further comprising:

means for canceling the handover to network service via the second RAT before completing the handover;

means for receiving the retained MS information; and

means for performing network re-entry using the received retained MS information to restore communication via the first RAT.

13. The apparatus of claim 9, wherein the means for entering the idle mode comprises means for entering the idle mode before accessing network service via the second RAT during the handover.

14. The apparatus of claim 9, further comprising means for requesting network service via the first RAT to increase a period between transmitting paging messages before entering the idle mode.

15. The apparatus of claim 14, wherein the means for requesting network service via the first RAT to increase the period between transmitting the paging messages comprises:

means for setting a Paging Cycle value in a Paging Cycle Request field of a De-Registration Request (DREG-REQ) message; and

means for transmitting the DREG-REQ message.

16. The apparatus of claim 15, wherein the means for setting the Paging Cycle value comprises:

means for determining a maximum time to return to network service via the first RAT and a number of paging retries for network service via the first RAT;

means for calculating a minimum Paging Cycle value by dividing the maximum time to return by the number of paging retries minus one; and

means for setting the Paging Cycle value greater than or equal to the minimum Paging Cycle value.

17. An apparatus for performing handover between network service via first and second radio access technologies (RATs), comprising:

logic for communicating via the first RAT;

logic for triggering a handover to network service via the second RAT, wherein the first and second RATs are different; and

logic for entering an idle mode before completing the handover to network service via the second RAT.

18. The apparatus of claim 17, further comprising logic for requesting network service via the first RAT to retain mobile station (MS) information before entering the idle mode.

19. The apparatus of claim 18, wherein the MS information comprises at least one of service information, operational information, or service flow state information.

20. The apparatus of claim 18, further comprising:

logic for canceling the handover to network service via the second RAT before completing the handover;

a receiver configured to receive the retained MS information; and

logic for performing network re-entry using the received retained MS information to restore communication via the first RAT.

21. The apparatus of claim 17, wherein the logic for entering the idle mode comprises logic for entering the idle mode before accessing network service via the second RAT during the handover.

22. The apparatus of claim 17, further comprising logic for requesting network service via the first RAT to increase a period between transmitting paging messages before entering the idle mode.

23. The apparatus of claim 22, wherein the logic for requesting network service via the first RAT to increase the period between transmitting the paging messages comprises:

logic for setting a Paging Cycle value in a Paging Cycle Request field of a De-Registration Request (DREG-REQ) message; and

a transmitter configured to transmit the DREG-REQ message.

24. The apparatus of claim 23, wherein the logic for setting the Paging Cycle value comprises:

logic for determining a maximum time to return to network service via the first RAT and a number of paging retries for network service via the first RAT;

logic for calculating a minimum Paging Cycle value by dividing the maximum time to return by the number of paging retries minus one; and

logic for setting the Paging Cycle value greater than or equal to the minimum Paging Cycle value.

25. A computer-program product for performing handover between network service via first and second radio access technologies (RATs), the computer-program product comprising a computer-readable medium having instructions stored thereon, the instructions being executable by one or more processors and the instructions comprising:

instructions for communicating via the first RAT;

instructions for triggering a handover to network service via the second RAT, wherein the first and second RATs are different; and

instructions for entering an idle mode before completing the handover to network service via the second RAT.

26. The computer-program product of claim 25, further comprising instructions for requesting network service via the first RAT to retain mobile station (MS) information before entering the idle mode.

27. The computer-program product of claim 26, wherein the MS information comprises at least one of service information, operational information, or service flow state information.

28. The computer-program product of claim 26, further comprising:

instructions for canceling the handover to network service via the second RAT before completing the handover;

instructions for receiving the retained MS information; and

instructions for performing network re-entry using the received retained MS information to restore communication via the first RAT.

29. The computer-program product of claim 25, wherein the instructions for entering the idle mode comprise instructions for entering the idle mode before accessing network service via the second RAT during the handover.

30. The computer-program product of claim 25, further comprising instructions for requesting network service via the first RAT to increase a period between transmitting paging messages before entering the idle mode.

31. The computer-program product of claim 30, wherein the instructions for requesting network service via the first RAT to increase the period between transmitting the paging messages comprise:

instructions for setting a Paging Cycle value in a Paging Cycle Request field of a De-Registration Request (DREG-REQ) message; and

instructions for transmitting the DREG-REQ message.

32. The computer-program product of claim 31, wherein the instructions for setting the Paging Cycle value comprise:

instructions for determining a maximum time to return to network service via the first RAT and a number of paging retries for network service via the first RAT;

instructions for calculating a minimum Paging Cycle value by dividing the maximum time to return by the number of paging retries minus one; and

instructions for setting the Paging Cycle value greater than or equal to the minimum Paging Cycle value.