Mobility parameter adjustment and mobility state estimation in heterogeneous networks

• US 9,277,475 B2
• Filed: 04/11/2014
• Issued: 03/01/2016
• Est. Priority Date: 03/16/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Song, Yi, Bontu, Chandra Sekhar, Cai, Zhijun
• Primary Examiner(s): PHAM, TIMOTHY X
• Application Number:
  US14/251,401
• Publication Number:
  US 20140220979A1
• Time in Patent Office: 690 Days
• Field of Search: 455/436
• US Class Current: 1/1
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

Systems and methods for mobility parameter adjustment and mobility state estimation in heterogeneous networks are provided. The mobility parameters may be adjusted based on the cell change types associated with the mobility procedure. The mobility procedure may be a cell handover procedure or a cell reselection procedure. The cell change type may be dependent on the transmission power level of the UE'"'"'s serving cell and neighboring cells. In some implementations, the UE may provide a speed information to the serving cell such that the serving eNB may prioritize or optimize the mobility procedure for the UE. The UE may also estimate its mobility state by counting the number of cell changes within certain period of time and applying scaling factors to the number of cell changes based on the associated cell change types.

Claims

1. A method of operating user equipment (UE) in a wireless communications network, the method comprising:

identifying, by the UE, a target cell type associated with a neighboring cell;

in response to identifying the target cell type associated with the neighboring cell, determining, by the UE, a time-to-trigger parameter, wherein the time-to-trigger parameter is determined by applying a scaling factor associated with the target cell type to a nominal time-to-trigger value, the scaling factor associated with the target cell type is based, at least in part, on a transmission power level of the neighboring cell and a transmission power level of the UE'"'"'s serving cell; and

executing, by the UE, a mobility procedure with the neighboring cell using the time-to-trigger parameter.

2. The method of claim 1, wherein the mobility procedure comprises a cell handover procedure.

3. The method of claim 2, wherein the cell handover procedure includes a procedure for the UE to change its serving cell in a connected mode.

4. The method of claim 1, wherein the UE is associated with a current cell of a first cell type, and wherein the target cell type is a second cell type.

5. The method of claim 4, wherein the first cell type is one of a macro, pico, relay, or femto cell, and wherein the second cell type is one of a macro, pico, relay, or femto cell.

6. The method of claim 1, further comprising receiving, by the UE, the time-to-trigger parameter from a base station, using a radio resource control (RRC) message.

7. The method of claim 1, further comprising receiving, by the UE, the scaling factor associated with the target cell type from a base station, using a radio resource control (RRC) message.

8. The method of claim 1, wherein the transmission power of the neighboring cell is signaled to the serving cell via a backhaul interface.

9. The method of claim 1, wherein the mobility procedure comprises a cell reselection procedure.

10. The method of claim 1, wherein the cell reselection procedure includes a procedure for the UE to change its serving cell in an idle mode.

11. The method of claim 1, further comprising receiving, by the UE, at least one of an indication of the transmission power level of the neighboring cell or an indication of the transmission power level of the UE'"'"'s serving cell.

12. User equipment (UE) for operating in a wireless communications network, comprising one or more processors configured to:

identify a target cell type associated with a neighboring cell;

in response to identifying the target cell type associated with the neighboring cell, determine a time-to-trigger parameter, wherein the time-to-trigger parameter is determined by applying a scaling factor associated with the target cell type to a nominal time-to-trigger value, the scaling factor associated with the target cell type is based, at least in part, on a transmission power level of the neighboring cell and a transmission power level of the UE'"'"'s serving cell; and

execute a mobility procedure with the neighboring cell using the time-to-trigger parameter.

13. The user equipment of claim 12, wherein the mobility procedure comprises a cell handover procedure.

14. The user equipment of claim 13, wherein the cell handover procedure includes a procedure for the UE to change its serving cell in a connected mode.

15. The user equipment of claim 12, wherein the UE is associated with a current cell of a first cell type, and wherein the target cell type is a second cell type, wherein the first cell type is one of a macro, pico, relay, or femto cell, and wherein the second cell type is one of a macro, pico, relay, or femto cell.

16. The user equipment of claim 12, the one or more processors further configured to receive the time-to-trigger parameter from a base station, using a radio resource control (RRC) message.

17. The user equipment of claim 12, the one or more processors further configured to receive the scaling factor associated with the target cell type from a base station, using a radio resource control (RRC) message.

18. The user equipment of claim 12, wherein the transmission power of the neighboring cell is signaled to the serving cell via a backhaul interface.

19. The user equipment of claim 12, wherein the mobility procedure is a cell reselection procedure.

20. The user equipment of claim 19, wherein the cell reselection procedure includes a procedure for the UE to change its serving cell in an idle mode.

21. The user equipment of claim 12, the one or more processors further configured to receive at least one of an indication of the transmission power level of the neighboring cell or an indication of the transmission power level of the UE'"'"'s serving cell.

22. A non-transitory computer-readable medium coupled to the one or more processors having instructions stored thereon which, when executed by the one or more processors, cause the one or more processors to perform operations comprising:

identifying a target cell type associated with a neighboring cell;

in response to identifying the target cell type associated with the neighboring cell, determining a time-to-trigger parameter, wherein the time-to-trigger parameter is determined by applying a scaling factor associated with the target cell type to a nominal time-to-trigger value, the scaling factor associated with the target cell type is based, at least in part, on a transmission power level of the neighboring cell and a transmission power level of the UE'"'"'s serving cell; and

executing a mobility procedure with the neighboring cell using the time-to-trigger parameter.

23. The computer-readable medium of claim 22, wherein the mobility procedure comprises a cell handover procedure.

24. The computer-readable medium of claim 23, wherein the cell handover procedure includes a procedure for the UE to change its serving cell in a connected mode.

25. The computer-readable medium of claim 22, wherein the computer readable medium is a user equipment (UE) associated with a current cell of a first cell type, and wherein the target cell type is a second cell type, wherein the first cell type is one of a macro, pico, relay, or femto cell, and wherein the second cell type is one of a macro, pico, relay, or femto cell.

26. The computer-readable medium of claim 22, the operations further comprising receiving the time-to-trigger parameter from a base station, using a radio resource control (RRC) message.

27. The computer-readable medium of claim 22, the operations further comprising receiving the scaling factor associated with the target cell type from a base station, using a radio resource control (RRC) message.

28. The computer-readable medium of claim 22, wherein the transmission power of the neighboring cell is signaled to the serving cell via a backhaul interface.

29. The computer-readable medium of claim 22, wherein the mobility procedure is a cell reselection procedure.

30. The computer-readable medium of claim 29, wherein the cell reselection procedure includes a procedure for the UE to change its serving cell in an idle mode.

31. The computer-readable medium of claim 22, the operations further comprising receiving at least one of an indication of the transmission power level of the neighboring cell or an indication of the transmission power level of the UE'"'"'s serving cell.