Operation in Case of Radio Link Failure

• US 20120142336A1
• Filed: 08/07/2009
• Published: 06/07/2012
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: HMD Global Oy
• Original Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Inventors: Van Phan, Vinh, Yu, Ling, Horneman, Kari Veikko
• Granted Patent: US 8,818,381 B2
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 76/19 Connection re-establishment
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

Attempting recovery from an unexpected radio link failure. A backup user context is created for a terminal device served currently by a relay base station relaying a radio connection between the terminal device and fixed cellular network infrastructure including a fixed base station communicating with the relay base station, wherein the backup user context is prepared for use in case of an unexpected radio link failure. Upon detection of the radio link failure in a primary user context being used in the communication, the backup user context is applied before the terminal device enters an idle state as a result of the radio link failure.

Claims

1. A method, comprising:

creating a backup user context for a terminal device served currently by a relay base station relaying a radio connection between the terminal device and fixed cellular network infrastructure comprising a fixed base station communicating with the relay base station, wherein the backup user context is prepared for use in case of an unexpected radio link failure; and

applying the backup user context upon detection of a radio link failure in a primary user context being used in the communication and before the terminal device enters an idle state as a result of the radio link failure.

2. The method of claim 1, wherein the terminal device applies the backup user context without reception of a command to apply the backup user context from the relay base station.

3. The method of claim 1, wherein the backup user context for the terminal device is created regardless of the channel state between the fixed base station and in the terminal device.

4. The method of claim 1, further comprising:

configuring the terminal device to store an identifier of the fixed base station in the backup user context stored in the terminal device; and

configuring the fixed base station to store an identifier of the terminal device in the backup user context stored in the fixed cellular network infrastructure.

5. The method of claim 1, wherein the relay base station is a mobile relay base station, the method further comprising:

updating the backup user context when the mobile relay base station is handed over to another fixed base station of the fixed cellular network infrastructure.

6. The method of claim 1, further comprising:

configuring the terminal device to store communication parameters to be used when the backup user context is applied.

7. The method of claim 6, wherein the stored communication parameters include carrier information of the fixed base station, an identifier of the terminal device in the backup user context, a transmission timing advance used by the relay base station in communication with the fixed base station and a scheduling request configuration, the method further comprising:

accessing the fixed base station by using the stored communication parameters upon detection of the radio link failure.

8. The method of claim 1, further comprising in the terminal device:

accessing the fixed base station associated with the stored backup user context before entering the idle state and upon detection of the radio link failure in the terminal device; and

negotiating recovery of the radio link between the fixed network infrastructure and the terminal device by applying the backup user context as a primary user context.

9. The method of claim 1, further comprising:

exchanging information related to the primary user context between the relay base station and the fixed base station when applying the backup user context for use between the fixed base station and the terminal device.

10. The method of claim 1, further comprising:

negotiating, after detection of the radio link failure, release of the primary user context of the terminal device used in communication with the relay base station before the radio link failure.

24. An apparatus comprising means for executing the method according to claim 1.

25. A computer program product embodied on a distribution medium readable by a computer and comprising program instructions which, when loaded into an apparatus, execute the method according to claim 1.

11. An apparatus comprising communication control circuitry configured to:

create of a backup user context for a terminal device served currently by a relay base station relaying a radio connection between the terminal device and fixed cellular network infrastructure comprising a fixed base station communicating with the relay base station, wherein the backup user context is prepared for use in case of an unexpected radio link failure, and

apply the backup user context upon detection of a radio link failure in a primary user context being used in the communication and before the terminal device enters an idle state as a result of the radio link failure.

12. The apparatus of claim 11, wherein the apparatus is applicable to the terminal device and is further configured to control the terminal device to apply the backup user context without reception of a command to apply the backup user context from the relay base station.

13. The apparatus of claim 11, wherein the communication control circuitry is further configured to create the backup user context for the terminal device regardless of the channel state between the fixed base station and in the terminal device.

14. The apparatus of claim 11, wherein the relay base station is a mobile relay base station, and wherein the communication control circuitry is further configured to update the backup user context when the mobile relay base station is handed over to another fixed base station of the fixed cellular network infrastructure.

15. The apparatus of claim 11, wherein the communication control circuitry is further configured to configure the terminal device to store communication parameters to be used when the backup user context is applied.

16. The apparatus of claim 15, wherein the stored communication parameters include carrier information of the fixed base station, an identifier of the terminal device in the backup user context, a scheduling request configuration and/or transmission timing advance used by the relay base station in communication with the fixed base station, and wherein the communication control circuitry is applicable to the terminal device and is further configured to access the fixed base station by using the stored communication parameters upon detection of the radio link failure.

17. The apparatus of claim 11, wherein the apparatus is applicable to the terminal device and is further configured to access the fixed base station associated with the stored backup user context before entering the idle state and upon detection of the radio link failure in the terminal device, and to negotiate the recovery of the radio link between the fixed network infrastructure and the terminal device by applying the backup user context as a primary user context.

18. The apparatus of claim 11, wherein the apparatus is applicable to the relay base station or the fixed base station, and wherein the communication control circuitry is further configured to exchange information related to the primary user context between the relay base station and the fixed base station when applying the backup user context for use between the fixed base station and the terminal device.

19. The apparatus of claim 11, wherein the communication control circuitry is further configured to configure the terminal device to store an identifier of the fixed base station in the backup user context stored in the terminal device.

20. The apparatus of claim 11, wherein the communication control circuitry is further configured to configure the fixed base station to store an identifier of the terminal device in the backup user context stored in the fixed cellular network infrastructure.

21. The method of claim 11, wherein the apparatus is applicable to the relay base station and is further configured to release, after the detection of the radio link failure, the primary user context of the terminal device used in communication with the relay base station before the radio link failure.

22. A terminal device of a cellular telecommunication system, comprising the apparatus according to claim 11, a memory unit configured to store parameters pertaining to the backup user context, and radio interface components providing the terminal device with radio communication capabilities.

23. A base station of a cellular telecommunication system, comprising the apparatus according to claim 18, an interface to a memory unit storing the backup user context, and radio interface components to providing the base station with radio communication capabilities.