Handover-related radio link failure detection

• US 8,559,397 B2
• Filed: 11/19/2009
• Issued: 10/15/2013
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Huang, Jing-Bo, Kim, Yeong-Seok, Lee, Chung-keun
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): SHARMA, GAUTAM
• Application Number:
  US12/622,098
• Publication Number:
  US 20110117908A1
• Time in Patent Office: 1,426 Days
• Field of Search: None
• US Class Current: 370/332
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

A Base Station (BS) apparatus, for detecting a HandOver (HO)-related Radio Link Failure (RLF) in a wireless communication, and method for its operation, are provided. The method includes receiving an HO request from another BS for a User Equipment (UE) that has an established connection with the BS, receiving a connection reestablishment request from the UE after an HO of the UE to the other BS has been performed, determining if the connection reestablishment request is received prior to the expiration of a timer, and if it is determined that the connection reestablishment request is received from the UE prior to the expiration of a timer, determining that an RLF occurred due to a too early HO triggering.

Claims

1. A method for operating a Base Station (BS) for detecting a too early HandOver (HO)-related Radio Link Failure (RLF) in a wireless communication system, the method comprising:

receiving an HO request from another BS for a User Equipment (UE) that has an established connection with the BS, wherein the HO request includes at least one identifier;

receiving a connection reestablishment request from the UE after an HO of the UE to the other BS has been performed, wherein the connection reestablishment request includes at least one identifier;

determining if the connection reestablishment request is received prior to the expiration of a timer;

determining if the at least one identifier included in the HO request received from the other BS and the connection reestablishment request received from the UE are identical;

if it is determined that the connection reestablishment request is received from the UE prior to the expiration of a timer, determining that an RLF occurred due to a too early HO triggering;

if it is determined that the RLF occurred due to a too early HO triggering, sending a report to a Self-Organizing Network (SON) Server indicating that the RLF occurred due to the too early HO triggering, and

receiving a message from the SON Server comprising at least a timer setting corresponding to an amount of time for determining whether an RLF occurs due to too early HO triggering, wherein the timer setting is configured based on the report sent to the SON Server.

2. The method of claim 1, wherein the timer is initiated upon receiving the HO request from the other BS.

3. The method of claim 1, further comprising sending a report to the other base station indicating that the RLF occurred due to the too early HO triggering.

4. The method of claim 1,

wherein it is determined that the RLF occurred due to the too early HO triggering, if it is determined that the connection reestablishment request is received from the UE prior to the expiration of a timer, and if it is determined that the at least one identifier included in the HO request received from the other BS and connection reestablishment request received from the UE are identical.

5. The method of claim 4, wherein the at least one identifier comprises at least one of an identifier of the UE assigned by the other BS and a cell identifier of the other BS.

6. The method of claim 4, further comprising storing the at least one identifier received in the HO request from the other BS.

7. The method of claim 1, wherein the HO request is received from the other BS via an X2 interface.

8. The method of claim 1, wherein the HO request is received from the other BS via an S1 interface.

19. The method of claim 1, further comprising receiving a message from the SON Server, wherein the message comprises new HO parameter settings.

20. The method of claim 19, wherein the message received from the SON Server comprises configuration settings relating to an amount of time during which the timer operates from when the timer is initialized and when the time expires.

21. The method of claim 1, wherein the determining if the at least one identifier included in the HO request received from the other BS and the connection reestablishment request received from the UE are identical comprises:

comparing the at least one identifier included in the connection reestablishment request with a corresponding at least one identifier buffered in the BS.

9. A Base Station (BS) apparatus for detecting a too early HandOver (HO)-related Radio Link Failure (RLF) in a wireless communication system, the apparatus comprising:

a first receiver for receiving signals from another BS;

a second receiver for receiving signals from a User Equipment (UE);

a first transmitter for transmitting signals to a Self-Organizing Network (SON) Server;

a controller for controlling to receive an HO request via the first receiver from the other BS for the UE that has an established connection with the BS, wherein the HO request includes at least one identifier, for controlling to receive via the second receiver a connection reestablishment request from the UE after an HO of the UE to the other BS has been performed, wherein the connection reestablishment request includes at least one identifier, for determining if the connection reestablishment request is received prior to the expiration of a timer, for determining if the at least one identifier included in the HO request received from the other BS and the connection reestablishment request received from the UE are identical, if it is determined that the connection reestablishment request is received from the UE prior to the expiration of a timer, for determining that an RLF occurred due to a too early HO triggering, and if it is determined that the RLF occurred due to a too early HO triggering, for controlling to send a report to the SON Server via the first transmitter that indicates that the RLF occurred due to the too early HO triggering, and for controlling to receive a message from the SON Server comprising at least a timer setting corresponding to an amount of time for determining whether an RLF occurs due to too early HO triggering, wherein the timer setting is configured based on the report sent to the SON Server.

10. The apparatus of claim 9, wherein the controller initiates the timer when the HO request is received via the first receiver from the other BS.

11. The apparatus of claim 9, further comprising a first transmitter for transmitting signals to the other BS,

wherein the controller controls to send a report to the other base station via the first transmitter that indicates that the RLF occurred due to the too early HO triggering.

12. The apparatus of claim 9,

wherein the controller determines that the RLF occurred due to the too early HO triggering, if it is determined that the connection reestablishment request is received from the UE prior to the expiration of a timer, and if it is determined that the at least one identifier included in the HO request received from the other BS and connection reestablishment request received from the UE are identical.

13. The apparatus of claim 12, wherein the at least one identifier comprises at least one of an identifier of the UE assigned by the other BS and a cell identifier of the other BS.

14. The apparatus of claim 12, further wherein the controller stores the at least one identifier received in the HO request from the other BS via the first receiver.

15. The apparatus of claim 9, wherein the HO request is received from the other BS via the first receiver is received via an X2 interface.

16. The apparatus of claim 9, wherein the HO request is received from the other BS via the first receiver is received via an S1 interface.

17. The apparatus of claim 9, wherein the first receiver is configured for receiving signals from the SON, and wherein the signals comprise a message from the SON Server that comprises new HO parameter settings.

18. The apparatus of claim 17, wherein the message received from the SON Server comprises configuration settings relating to an amount of time during which the timer operates from when the timer is initialized and when the time expires.

22. The apparatus of claim 9, wherein the determining if the at least one identifier included in the HO request received from the other BS and the connection reestablishment request received from the UE are identical comprises:

comparing the at least one identifier included in the connection reestablishment request with a corresponding at least one identifier buffered in the BS.