RADIO-LINK RELIABILITY USING MULTI-CARRIER CAPABILITY IN WIRELESS BROADBAND SYSTEMS

• US 20110110227A1
• Filed: 06/24/2010
• Published: 05/12/2011
• Est. Priority Date: 11/06/2009
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Yang, Xiangying, Etemad, Kamran
• Granted Patent: US 8,792,328 B2
• Time in Patent Office: Days
• US Class Current: 370/228
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Embodiments of a system and methods for improving radio link reliability using multi-carrier capability in wireless systems are generally described herein. Other embodiments may be described and claimed.

Claims

1. A method for multicarrier switching, comprising:

associating a user equipment (UE), wherein the UE is configured for communication over a plurality of carriers, with a base station (BS);

monitoring a link quality on a primary carrier used by the UE, wherein the UE operates on the plurality of carriers comprising a primary carrier and one or more secondary carriers;

detecting degradation of the link quality on the primary carrier;

determining if recovery on the primary carrier is possible;

declaring a radio link failure (RLF) on the primary carrier, wherein the RLF is declared by the UE;

identifying the one or more secondary carriers;

selecting a target secondary carrier from the one or more secondary carriers; and

establishing a new primary carrier on the target secondary carrier.

2. The method of claim 1, further including attempting a recovery procedure on the primary carrier if recovery on the primary carrier is possible.

3. The method of claim 2, wherein the UE is configured to communicate using a mobile WiMAX protocol.

4. The method of claim 1, wherein the RLF is transmitted to the BS.

5. The method of claim 1, further including receiving a keep-alive probe from the BS to re-establish communications with the UE on the primary carrier.

6. The method of claim 1, wherein the BS:

identifies the one or more secondary carriers;

selecting a target secondary carrier from the one or more secondary carriers; and

establishes a new primary carrier on the target secondary carrier.

7. The method of claim 1, wherein the target secondary carrier is an alternate carrier with a valid integrity protection from a previously established security context.

8. A method for multicarrier switching, comprising:

forming a communications link over a primary carrier, wherein a MAC control protocol is transferred over the primary carrier;

receiving a link recovery request from a multicarrier user equipment (UE);

locating a context retain timer in a base station (BS);

investigating the context retain timer to determine whether the context retain timer is expired;

determining if the link recovery request is received over the primary carrier;

identifying that the link recovery request is received over a secondary carrier;

switching the MAC control protocol from the primary carrier to the secondary carrier as a candidate primary carrier;

initiating a recovery procedure over the candidate primary carrier; and

establishing the candidate primary carrier as a new primary carrier between the BS and the multicarrier UE.

9. The method of claim 8, further including instructing the multicarrier UE to perform a full network entry if the context retain timer is expired.

10. The method of claim 9, wherein the BS is configured to communicate over a mobile WiMAX protocol.

11. The method of claim 8, further including initiating a recovery procedure over the primary carrier.

12. The method of claim 8, wherein the recovery procedure is initiated using a MC-CMD message.

13. The method of claim 8, wherein the candidate primary carrier is selected based at least in-part on a requisite link quality.

14. The method of claim 8, wherein the BS does not have to perform a full network entry procedure to form a communications link with the multicarrier UE over the new primary carrier.

15. A user equipment (UE) comprising a media access control (MAC) layer and a physical (PHY) layer, wherein the UE is configured to perform multicarrier switching between a primary carrier and a secondary carrier by detecting degradation of a link quality on the primary carrier, attempting a recovery procedure on the primary carrier, identifying one or more secondary carriers, selecting a target secondary carrier from the one or more secondary carriers, and establishing a new primary carrier on the target secondary carrier.

16. The UE of claim 15, wherein the UE is configured to communicate using a long term evolution (LTE) protocol.

17. The UE of claim 15, further comprising declaring a radio link failure (RLF).

18. The UE of claim 17, further comprising transmitting the RLF to a base station.

19. The UE of claim 15, further comprising receiving a keep-alive probe from a BS to re-establish communications with the UE on the primary carrier.

20. The UE of claim 15, wherein the UE further comprises multiple antennas.