METHOD OF SUPPORTING HANDOVER IN A WIRWLESS COMMUNICATION SYSTEM

• US 20100227614A1
• Filed: 03/22/2007
• Published: 09/09/2010
• Est. Priority Date: 03/22/2006
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Young Dae, Park, Sung Jun, Chun, Sung Duck
• Granted Patent: US 8,971,288 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 47/193 at the transport layer, e.g. TCP related
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off

Abstract

Disclosed are methods of performing handover and supporting thereof in a mobile communication system. The method of supporting handover at a first network entity in a mobile communication system comprises transmitting a plurality of data blocks of a first layer to a user equipment (UE), checking whether each of the plurality of data blocks is successfully transmitted to the user equipment (UE), and transmitting to a second network entity at least one data block of the first layer excluding a data block which is successfully transmitted to the user equipment (UE) among the plurality of data blocks of the first layer, the second network entity being a target network entity for handover of the user equipment (UE).

Claims

1. A method of supporting handover at a first network entity in a mobile communication system, the method comprising:

transmitting a plurality of data blocks of a first layer to a user equipment;

checking whether each of the plurality of data blocks is successfully transmitted to the user equipment; and

transmitting to a second network entity at least one data block of the first layer excluding a data block which is successfully transmitted to the user equipment among the plurality of data blocks of the first layer, the second network entity being a target network entity for handover of the user equipment.

2. The method of claim 1, wherein the first layer is a radio link control (RLC) layer having an acknowledged mode (AM) entity.

3. The method of claim 2, wherein the at least one data block includes a data block for which a negative reception acknowledgement is received from the user equipment.

4. The method of claim 3, wherein the at least one data block includes a data block included in a data block of a lower layer for which a negative acknowledgement signal (NACK) is received from the user equipment.

5. The method of claim 4, wherein the at least one data block includes a data block which is not transmitted to the user equipment.

6. The method of claim 2, wherein a data block of the first layer is an RLC protocol data unit (PDU).

7. The method of claim 1, wherein the first network entity is a source eNode B (eNB).

8. The method of claim 7, wherein the second network entity is a target eNode B (eNB).

9. The method of claim 4, wherein the lower layer is a medium access control (MAC) layer and the data block of the lower layer is a MAC protocol data unit (PDU).

10. The method of claim 1, wherein the first and second network entities have different acknowledged mode (AM) entities.

11. A method of supporting handover at a first network entity in a mobile communication system, the method comprising:

transmitting a plurality of first data blocks of a first layer to a user equipment, each of the plurality of first data blocks including at least a part of a second data block transferred from an upper layer;

checking whether each of the plurality of first data blocks is transmitted successfully to the user equipment; and

transmitting to a second network entity at least one second data block included in a first data block of the first layer excluding a first data block which is successfully transmitted to the user equipment among the plurality of first data blocks, the second network entity being a target network entity for handover of the user equipment.

12. The method of claim 11, wherein the first layer is a radio link control (RLC) layer having an acknowledged mode (AM) entity.

13. The method of claim 12, wherein the at least one second data block includes a second data block included in a first data block for which a negative reception acknowledgement is received from the user equipment.

14. The method of claim 13, wherein the at least one second data block includes a second data block included in a third data block of a lower layer for which a negative acknowledgement signal (NACK) is received from the user equipment.

15. The method of claim 14, wherein the at least one second data block includes a second data block included in a first data block which is not transmitted to the user equipment.

16. The method of claim 12, wherein a first data block of the first layer is an RLC protocol data unit (PDU).

17. The method of claim 16, wherein a second data block of the upper layer is an RLC service data unit (SDU).

18. The method of claim 11, wherein the first network entity is a source eNode B (eNB).

19. The method of claim 18, wherein the second network entity is a target eNode B (eNB).

20. The method of claim 14, wherein the lower layer is a medium access control (MAC) layer and the third data block of the lower layer is a MAC protocol data unit (PDU).

21. The method of claim 11, wherein the first and second network entities have different acknowledged mode (AM) entities.

22. A method of transmitting status report for supporting handover at a user equipment in a mobile communication system, comprising:

checking whether a handover command is received from a first network entity; and

transmitting status report for at least one data block transmitted from the first network entity to at least one of the first network entity and a second network entity if the handover command is received from the first network entity, the second network entity being a target network entity for handover of the user equipment.

23. The method of claim 22, wherein the status report includes a positive reception acknowledgement or a negative reception acknowledgement for each of a plurality of data units received from the first network entity during a pre-determined time period.

24. The method of claim 23, wherein the plurality of data units are service data units (SDUs) of a radio link control (RLC) layer.

25. The method of claim 23, wherein the plurality of data units are protocol data units (PDUs) of a radio link control (RLC) layer.

26. The method of claim 22, wherein the status report is included in a handover confirm message to be transmitted the second network entity.

27. The method of claim 22. wherein the status report is transmitted to at least one of the first network entity and the second network entity through radio link control (RLC) signaling or radio resource control (RRC) signaling.

28. The method of claim 22, wherein the first network entity is a source eNode B (eNB).

29. The method of claim 28, wherein the second network entity is a target eNode B (eNB).

30. The method of claim 23, further comprising receiving from the second network entity at least one data block excluding a data block for which the positive reception acknowledgement is transmitted among the plurality of data blocks.