Handover failure procedures in communication systems

• US 9,544,828 B2
• Filed: 12/04/2008
• Issued: 01/10/2017
• Est. Priority Date: 12/05/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kitazoe, Masato
• Primary Examiner(s): TANG, KIET G
• Application Number:
  US12/328,606
• Publication Number:
  US 20090149180A1
• Time in Patent Office: 2,959 Days
• Field of Search: 370/331, 455/436, 455/422.1, 455/414.1
• US Class Current: 1/1
• CPC Class Codes: H04W 36/26 by agreed or negotiated communication parameters

Abstract

When a handover failure occurs and/or is anticipated to occur, an optimized cell can be selected and user equipment can transfer to the optimized cell. This optimized cell can differ from a previous cell based upon various factors such as anticipated interference and load balancing. Once there is identification of a handover failure a cell can return to a previous frequency and an appropriate cell can be determined. Instruction of the cell that should be used can be determined by user equipment as well as from a network entity.

Claims

1. A method for managing a wireless communication handover operable upon a user equipment (UE), comprising:

identifying, by the user equipment, a handover failure in relation to transferring of the user equipment among base stations;

selecting, by the user equipment, an optimized cell in which to transfer the user equipment when the handover failure is identified, wherein the user equipment selects the optimized cell by evaluating at least one cell characteristic and selecting the cell based on a result of the evaluation; and

reverting operation of the user equipment to a previous cell when the optimized cell is the previous cell, wherein the pervious cell is a prior cell to which the UE unsuccessfully attempted to handover.

2. The method of claim 1, wherein selecting the optimized cell includes at least one of:

selecting a cell anticipated to have a lowest amount of interference for the user equipment; and

selecting a cell as a function of load balancing among at least two cells.

3. The method of claim 1, further comprising reverting operation of the user equipment to a previous frequency upon attempting the handover.

4. A user equipment (UE), comprising hardware components including:

an identifier that identifies a handover failure in relation to transferring the user equipment among base stations; and

a designator that selects an optimized cell in which to transfer the user equipment when the handover failure is identified, wherein the designator selects the optimized cell by evaluating at least one cell characteristic and selecting the cell based on a result of the evaluation,

wherein the designator reverts operation of the user equipment to a previous cell when the optimized cell is the previous cell, wherein the pervious cell is a prior cell to which the UE unsuccessfully attempted to handover.

5. The user equipment of claim 4, wherein selection of the optimized cell includes at least one of:

selection of a cell anticipated to have a lowest amount of interference for the user equipment; and

selection of a cell as a function of load balancing among at least two cells.

6. The user equipment of claim 4, further comprising a changer that reverts operation of the user equipment to a previous frequency upon attempting the handover.

7. A user equipment (UE), comprising:

means for identifying a handover failure in relation to transferring of the user equipment among base stations;

means for selecting an optimized cell in which to transfer the user equipment when the handover failure is identified, wherein the means for selecting the optimized cell selects the optimized cell by evaluating at least one cell characteristic and selecting the cell based on a result of the evaluation; and

means for reverting operation of the user equipment to a previous cell if the optimized cell is the previous cell, wherein the pervious cell is a prior cell to which the UE unsuccessfully attempted to handover.

8. The user equipment of claim 7, wherein the means for selecting the optimized cell includes at least one of:

means for selecting a cell anticipated to have a lowest amount of interference for the user equipment; and

means for selecting a cell as a function of load balancing among at least two cells.

9. The user equipment of claim 7, further comprising means for reverting operation of the user equipment to a previous frequency upon attempting the handover.

10. A non-transitory computer-readable storage medium comprising:

a set of codes for causing a user equipment (UE) to identify a handover failure in relation to transferring of the user equipment among base stations;

a set of codes for causing the user equipment to select an optimized cell in which to transfer the user equipment when the handover failure is identified, wherein the set of codes for causing the user equipment to select the optimized cell includes a set of codes for causing the user equipment to evaluate at least one cell characteristic and a set of codes for causing the user equipment to select the cell based on a result of the evaluation; and

a set of codes for causing the user equipment to revert operation of the user equipment to a previous cell when the optimized cell is the previous cell, wherein the pervious cell is a prior cell to which the UE unsuccessfully attempted to handover.

11. The computer-readable medium of claim 10, wherein the set of codes for causing the user equipment to select the optimized cell includes at least one of:

a set of codes for causing the user equipment to select a cell anticipated to have a lowest amount of interference for the user equipment; and

a set of codes for causing the user equipment to select a cell as a function of load balancing among at least two cells.

12. The computer-readable medium of claim 10, further comprising a set of codes for causing the user equipment to revert operation of the user equipment to a previous frequency upon attempting the handover.

13. A user equipment (UE) comprising:

at least one processor configured to;

identify a handover failure in relation to transferring of the user equipment among base stations;

select an optimized cell in which to transfer the user equipment when the handover failure is identified, wherein the at least one processor is configured to select the optimized cell by evaluating at least one cell characteristic and selecting the cell based on a result of the evaluation;

revert operation of the user equipment to a previous cell when the optimized cell is the previous cell, wherein the pervious cell is a prior cell to which the UE unsuccessfully attempted to handover; and

a memory coupled to the at least one processor.

14. The user equipment of claim 13, wherein the at least one processor is configured to select the optimized cell by at least one of:

selecting a cell anticipated to have a lowest amount of interference for the user equipment; and

selecting a cell as a function of load balancing among at least two cells.

15. The user equipment of claim 13, wherein the at least one processor is further configured to revert operation of the user equipment to a previous frequency upon attempting the handover.