Method of reselecting a cell based on priorities

• US 8,121,602 B2
• Filed: 10/30/2008
• Issued: 02/21/2012
• Est. Priority Date: 10/30/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yi, Seung June, Lee, Young Dae, Chun, Sung Duck, Park, Sung Jun, Lee, Seon Don
• Primary Examiner(s): Karikari, Kwasi
• Application Number:
  US12/681,507
• Publication Number:
  US 20100216469A1
• Time in Patent Office: 1,209 Days
• Field of Search: 455/513, 455/512, 455/435.3, 455/436, 455/443, 455/448, 455/453, 455/464
• US Class Current: 455/436
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

A cell reselection method in a wireless communication system is described. A method of performing cell reselection based on priorities by a user equipment (UE) in a wireless communication system includes selecting one or more candidate cells satisfying a first criterion associated with priorities among a serving cell and neighbor cells, and camping on a cell satisfying a second criterion for cell reselection among the one or more candidate cells.

Claims

1. A method of performing cell reselection based on priorities by a user equipment (UE) in a wireless communication system, the method comprising the steps of:

selecting one or more candidate cells satisfying a first criterion associated with priorities among a serving cell and neighbor cells; and

camping on a cell satisfying a second criterion for cell reselection among the one or more candidate cells,

wherein the first criterion is UE-common or UE-specific, and

if there are two or more first criterions, a UE-specific first criterion has a priority over a UE-common first criterion.

2. The method of claim 1, wherein the priorities are related to frequencies, radio access technologies (RATs), cells, or any combination thereof.

3. The method of claim 1, wherein the priorities are UE-common or UE-specific.

4. The method of claim 1, wherein the first criterion is a minimum priority which should be satisfied by the candidate cells.

5. The method of claim 1, further comprising receiving the first criterion from a network.

6. The method of claim 5, wherein the first criterion is invalidated when a certain period of time has elapsed after the reception of the first criterion, or when a region, a cell or a group to which the UE belongs has been changed.

7. The method of claim 1, wherein the first criterion is used to distinguish between a suitable cell and an acceptable cell.

8. The method of claim 7, wherein if no cells satisfy the first criterion, the UE transitions to ‘

Any Cell Selection’

state.

9. The method of claim 7, wherein if any cell satisfies the first criterion, the UE transitions to ‘

Camped normally’

state.

10. The method of claim 1, wherein the second criterion comprises selecting the highest priority cell among one or more cells satisfying a specific signal characteristic value.

11. The method of claim 1, wherein the second criterion comprises selecting a cell having good signal characteristics.

12. The method of claim 11, wherein the second criterion comprises selecting a cell having good signal characteristics using a ranking procedure.

13. The method of claim 11, wherein if a signal characteristic value of the serving cell is equal to or more than a specific value, the selecting a cell having good signal characteristics is not performed.

14. The method of claim 1, wherein the cell reselection comprises at least one of intra-frequency cell reselection, inter-frequency cell reselection, and inter- radio access technology (RAT) cell reselection.

15. A method of performing cell reselection based on priorities in a wireless communication system, the method comprising the steps of:

determining whether or not a serving cell satisfies a first criterion associated with priorities; and

if the serving cell satisfies the first criterion, triggering a cell reselection procedure only when a signal characteristic value of the serving cell is equal to or less than a specific value,

wherein the first criterion is UE-common or UE-specific, and

if there are two or more first criterions, a UE-specific first criterion has a priority over a UE-common first criterion.

16. The method of claim 15, wherein the priorities are related to frequencies, radio access technologies (RATs), cells, or any combination thereof.

17. The method of claim 15, wherein the priorities are UE-common or UE-specific.

18. The method of claim 15, wherein the first criterion is a minimum priority which should be satisfied by the serving cell.

19. The method of claim 15, further comprising receiving the first criterion from a network.

20. The method of claim 15, wherein the first criterion is invalidated when a certain period of time has elapsed after the reception of the first criterion, or when a region, a cell or a group to which the UE belongs has been changed.

21. A method of transmitting control information associated with cell reselection in a wireless communication system, the method comprising the steps of:

transmitting a first message indicating information associated with priorities used during the cell reselection; and

transmitting a second message indicating a first criterion associated with priorities which should be satisfied by a serving cell and neighbor cells to be selected as a candidate cell, wherein the first criterion is UE-common or UE-specific, and if there are two or more first criterions, a UE-specific first criterion has a priority over a UE-common first criterion.

22. The method of claim 21, wherein the priorities are related to frequencies, radio access technologies (RATs), cells, or any combination thereof.

23. The method of claim 21, wherein the priorities are UE-common or UE-specific.

24. The method of claim 21, wherein the information associated with priorities is a neighbor cell list (NCL).

25. The method of claim 21, wherein the first criterion is a minimum priority which should be satisfied by the serving cell and the neighbor cells to be selected as the candidate cell.

26. The method of claim 21, wherein the first criterion is UE-common or UE-specific.