SCELL RADIO LINK MONITORING AND RADIO LINK FAILURE HANDLING

• US 20120281548A1
• Filed: 04/30/2012
• Published: 11/08/2012
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: HFI Innovation, Inc. (MediaTek, Inc.)
• Original Assignee: MediaTek, Inc.
• Inventors: Lin, Shiang-Jiun, Johansson, Per Johan Mikael, Chen, Yih-Shen
• Granted Patent: US 9,042,315 B2
• Time in Patent Office: Days
• US Class Current: 370/242
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

A method of radio link monitoring (RLM) and radio link failure (RLF) handling over a secondary serving cell (SCELL) is proposed. In a wireless network, a user equipment (UE) establishes a radio resource control (RRC) connection with a base station (eNB). The UE applies carrier aggregation for multiple component carriers (CCs) configured as multiple serving cells. The UE performs radio link monitoring over a primary serving cell (PCELL). The UE also performs radio link monitoring over a secondary serving cell (SCELL). The SCELL belongs to a CC group of one or more CCs, and used as a reference cell for the CC group. When SCELL performance is below pre-defined criteria, the UE and the eNB apply certain actions over the SCELL or all CCs in the CC group. The proposed SCELL RLM/RLF handling prevents spurious and uncontrollable uplink SCELL transmission and interference to other UEs.

Claims

1. A method, comprising:

establishing a radio resource control (RRC) connection by a user equipment (UE) with a base station, where the UE applies carrier aggregation for multiple component carriers (CCs);

performing radio link monitoring by the UE over a primary serving cell (PCELL);

performing radio link monitoring by the UE over a secondary serving cell (SCELL), wherein the SCELL belongs to a group of one or more CCs; and

applying an action when SCELL performance is below pre-defined criteria, wherein the action is applied over the SCELL or all CCs in the group.

2. The method of claim 1, wherein the SCELL is a reference cell that is used as pathloss reference and/or timing advance reference.

3. The method of claim 1, wherein the SCELL is used to perform random access channel (RACH) procedure.

4. The method of claim 1, wherein the radio link monitoring involves downlink monitoring based on Q_IN/Q_OUT measurements.

5. The method of claim 4, wherein the radio link monitoring involves radio link failure detection based on detecting physical layer problem of the RRC connection based on N310/N311/T310 mechanism.

6. The method of claim 1, wherein the radio link monitoring involves uplink-monitoring including radio link failure detection based on random access channel (RACH) failure detection and/or maximum number of radio link control (RLC) retransmissions.

7. The method of claim 1, wherein the action involves the UE notifying the base station at least one of a detected radio link failure of the SCELL, a deactivation of the SCELL, availability of problem event information gathered for the SCELL, and problem event information gathered for the SCELL.

8. The method of claim 1, wherein the action involves the UE autonomously stopping uplink transmission over the SCELL.

9. A user equipment (UE), comprising:

a radio resource control (RRC) connection management module that establishes an RRC connection with a base station, where the RRC connection is established over multiple component carriers (CCs);

a radio link monitoring module that performs radio link monitoring over a primary serving cell (PCELL) and over a secondary serving cell (SCELL), wherein the SCELL belongs to a group of one or more CCs; and

an SCELL configuration module that applies an action when SCELL performance is below a pre-defined criteria, wherein the action is applied over the SCELL or all CCs in the group.

10. The UE of claim 9, wherein the SCELL is a reference cell that is used as pathloss reference and/or timing advance reference.

11. The UE of claim 9, wherein the SCELL is used to perform random access channel (RACH) procedure.

12. The UE of claim 9, wherein the radio link monitoring involves downlink monitoring based on Q_IN/Q_OUT measurements.

13. The UE of claim 12, wherein the radio link monitoring involves radio link failure detection based on detecting physical layer problem of the RRC connection based on N310/N311/T310 mechanism.

14. The UE of claim 9, wherein the radio link monitoring involves uplink-monitoring including radio link failure detection based on random access channel (RACH) failure detection and/or maximum number of radio link control (RLC) retransmissions.

15. The UE of claim 9, wherein the action involves the UE notifying the base station at least one of a detected radio link failure of the SCELL, deactivation of the SCELL, availability of problem event information gathered for the SCELL, and the problem event information gathered for the SCELL.

16. The UE of claim 9, wherein the action involves the UE autonomously stopping uplink transmission over the SCELL.

17. A method, comprising:

establishing a radio resource control (RRC) connection with a user equipment (UE), where the RRC connection is established over multiple component carriers (CCs);

configuring one or more CCs as a CC group for the UE, wherein the group includes one secondary serving cell (SCELL);

receiving a notification from the UE, wherein the notification contains at least one of a detected radio link failure of the SCELL, a deactivation of the SCELL, availability of problem event information gathered for the SCELL, and the problem event information gathered for the SCELL; and

applying an action based on the received notification, wherein the action is applied over the SCELL and/or all CCs in the group.

18. The method of claim 17, wherein the SCELL is a reference cell that is used as pathloss reference and/or timing advance reference for the CC group.

19. The method of claim 17, wherein the SCELL is used to perform random access channel (RACH) procedure.

20. The method of claim 17, wherein the action involves deactivating or de-configuring the SCELL.

21. The method of claim 17, wherein the action involves requesting and retrieving gathered problem event information from the UE.