Method and apparatus for monitoring for a radio link failure

• US 8,711,709 B2
• Filed: 03/12/2010
• Issued: 04/29/2014
• Est. Priority Date: 03/12/2009
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Marinier, Paul, Terry, Stephen E., Somasundaram, Shankar, Wang, Peter S., Pelletier, Ghyslain, Rudolf, Marian, Gauvreau, Jean-Louis
• Primary Examiner(s): Elallam, Ahmed
• Application Number:
  US12/722,862
• Publication Number:
  US 20110021154A1
• Time in Patent Office: 1,509 Days
• Field of Search: 370/241, 370/242, 370/254, 370/329, 455/67.11, 455/423
• US Class Current: 370/242
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure
• CPC Class Codes: H04W 76/19 Connection re-establishment
• CPC Class Codes: H04W 76/38 triggered by timers

Abstract

Methods and apparatus are described for monitoring for a radio link failure in a long term evolution-advanced (LTE-A) system operated with carrier aggregation. The methods include criteria for determining radio link failure, recovery events, and the actions that a wireless transmit/receive unit (WTRU) may take upon the occurrence of such events.

Claims

1. A method, implemented by a wireless transmit/receive unit (WTRU), of monitoring for a radio link failure, the method comprising:

counting out-of-synch indications from each of a plurality of carriers with a physical downlink control channel (PDCCH) configured for the WTRU,

wherein the plurality of carriers with PDCCH configured includes a primary carrier with PDCCH configured associated with a base station and at least one secondary carrier with PDCCH configured associated with another base station;

initiating a recovery timer in the WTRU on a condition that a predefined number of out-of-synch indications from the at least one secondary carrier with PDCCH configured was counted;

counting in-synch indications from the at least one secondary carrier with PDCCH configured; and

transmitting a notification of radio link failure associated with the at least one secondary carrier with PDCCH configured to the primary carrier with PDCCH configured on a condition that the recovery timer expires before a predefined number of in-synch indications is counted.

2. The method of claim 1, wherein the primary carrier with PDCCH configured is selected from the plurality of carriers with PDCCH configured, wherein the selected primary carrier with PDCCH configured has the highest coverage among the plurality of carriers with PDCCH configured.

3. The method of claim 1, wherein the primary carrier with PDCCH configured is selected from the plurality of carriers with PDCCH configured that are in discontinuous reception (DRX) active time based on a predefined or signaled priority.

4. The method of claim 1, wherein the primary carrier with PDCCH configured is obtained from a network through radio resource control (RRC) signaling.

5. The method of claim 1, further comprising:

performing either a connection re-establishment procedure or a radio resource control (RRC) connection release procedure on a condition that a radio link failure is declared.

6. The method of claim 1, further comprising:

on a condition that a predefined number of in-synch indications was received from the at least one of the secondary component carriers before the recovery timer expires, stopping the recovery timer.

7. The method of claim 1, further comprising:

on a condition that a predefined number of in-synch indications was not received from the at least one secondary carrier with PDCCH configured before the recovery timer expires, performing a primary re-establishment procedure.

8. A method, implemented by a wireless transmit/receive unit (WTRU), of monitoring for a radio link failure, the method comprising:

counting out-of-synch indications from a primary component carrier and each of a plurality of secondary component carriers activated for the WTRU,

wherein the primary component carrier and the plurality of secondary component carriers are associated with different base stations;

initiating a recovery timer in the WTRU on a condition that a predefined number of out-of-synch indications from at least one of the secondary component carriers was counted;

counting in-synch indications from the at least one of the secondary component carriers; and

transmitting a radio link failure associated with the at least one of the secondary component carriers to the primary component carrier on a condition that the recovery timer expires before a predefined number of in-synch indications is counted.

9. The method of claim 8, wherein the primary component carrier is obtained from a network through radio resource control (RRC) signaling.

10. The method of claim 8, further comprising:

performing either a connection re-establishment procedure or a radio resource control (RRC) connection release procedure on a condition that a radio link failure is declared.

11. The method of claim 8, further comprising:

on a condition that a predefined number of in-synch indications was received from the at least one of the secondary component carriers before the recovery timer expires, stopping the recovery timer.

12. The method of claim 8, further comprising:

on a condition that a predefined number of in-synch indications was not received from the at least one of the secondary component carriers before the recovery timer expires, performing a primary re-establishment procedure.