Method and system for interference management in a spectrum shared by WAN and femto cells

• US 8,391,882 B2
• Filed: 10/22/2008
• Issued: 03/05/2013
• Est. Priority Date: 10/22/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sampath, Ashwin, Li, Husheng
• Primary Examiner(s): NGUYEN, HAI V
• Application Number:
  US12/256,069
• Publication Number:
  US 20100099431A1
• Time in Patent Office: 1,595 Days
• Field of Search: 455/454
• US Class Current: 455/454
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Devices and methods are provided for adapting to interference in a spectrum shared by a WAN macro cell and a femto cell. In particular, described herein are techniques for adapting to the presence of a jamming WAN access terminal (AT) by avoiding or selectively utilizing those bandwidth portions jammed by the WAN AT/AP. For example, the technique may involve intercepting a control message from the WAN AP to the WAN AT, and determining a spectrum resource that the WAN AT will use to communicate with the WAN AP based at least in part on information (e.g., a Cell Radio Network Temporary Identifier, a Media Access Control Identifier, etc.) in the control message.

Claims

1. A method for interference management in a spectrum shared by a WAN macro cell and a femto cell, comprising:

detecting a WAN access terminal (AT) in a coverage area of the femto cell;

accessing a control message sent by a WAN access point (AP) to the WAN AT;

determining a first resource of the spectrum that the WAN AT will use to communicate with the WAN AP based at least in part on the control message; and

assigning a second resource of the spectrum to a femto AT in the coverage area based at least in part on the determined first resource.

6. The method of claim 1, wherein the control message comprises a broadcast message from the WAN AP.

7. The method of claim 1, wherein the control message comprises at least one of an ACK message and a NACK message.

8. The method of claim 1, wherein determining comprises determining the first resource based on data relating to at least one of a forward link bandwidth configuration and a downlink bandwidth configuration.

9. The method of claim 1, wherein determining comprises determining the first resource based on data relating to at least one of a reverse link bandwidth configuration and an uplink bandwidth configuration.

10. The method of claim 1, wherein determining comprises determining the first resource based at least in part on at least one of sector ID data and system time data of the WAN AP.

11. The method of claim 1, wherein assigning comprises selecting the second resource based at least in part on a bandwidth portion that the WAN AT is expected to use to communicate with the WAN AP during a subsequent occurrence of an interlace.

12. The method of claim 1, wherein assigning comprises selecting an unjammed resource for the femto AT in response to at least one of the WAN AT and the WAN AP jamming at least one resource of the spectrum.

13. The method of claim 12, wherein selecting comprises calculating a bandwidth portion that will be assigned to the WAN AT during a subsequent occurrence of an interlace, the unjammed resource comprising an available bandwidth portion other than the calculated bandwidth portion.

14. The method of claim 1, wherein determining comprises inferring the first resource that is expected to be assigned to the WAN AT during a subsequent occurrence of an interlace based at least in part on the control message.

15. The method of claim 14, further comprising calculating whether co-assigning the first resource to the femto AT will increase a data transfer rate between the femto AT and a femto AP.

16. The method of claim 15, wherein the second resource comprises the first resource when it is calculated that co-assigning the first resource to the femto AT will increase the data transfer rate.

17. The method of claim 14, further comprising treating as erasure any data transferred on the first resource during the subsequent occurrence of the interlace, in response to determining that the data is unreliable.

18. The method of claim 17, wherein determining that the data is unreliable comprises determining that a signal energy level of the first resource exceeds a defined upper limit.

2. The method of claim wherein accessing comprises intercepting the control message.

3. The method of claim 2, further comprising receiving information from the WAN AT that facilitates intercepting the control message.

4. The method of claim 3, wherein receiving comprises receiving at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and a Media Access Control Identifier (MAC ID).

5. The method of claim 4, wherein the at least one of the C-RNTI and the MAC ID is sent from the WAN AP.

19. A communication device for interference management in a spectrum shared by a WAN macro cell and a femto cell, comprising:

a transceiver supporting a communication link with at least one femto access terminal (AT) in a coverage area of the femto cell;

at least one processor in operative communication with the transceiver;

a memory in operative communication with the at least one processor and comprising executable code for the at least one processor to;

detect a WAN AT in the coverage area;

access a control message sent by a WAN access point (AP) to the WAN AT;

determine a first resource of the spectrum that the WAN AT will use to communicate with the WAN AP based at least in part on the control message; and

assign a second resource of the spectrum to the at least one femto AT based at least in part on the determined first resource.

20. The device of claim 19, wherein the at least one processor is adapted to access by intercepting the control message.

21. The device of claim 20 wherein the at least one processor is adapted to receive information from the WAN AT that facilitates intercepting the control message.

22. The device of claim 21, wherein the received information comprises at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and a Media Access Control Identifier (MAC ID).

23. The device of claim 22, wherein the at least one of the C-RNTI and the MAC ID is sent from the WAN AP.

24. The device of claim 19, wherein the control message comprises a broadcast message from the WAN AP.

25. The device of claim 19, wherein the control message comprises at least one of an ACK message and a NACK message.

26. The device of claim 19, wherein the at least one processor is adapted to determine the first resource based on data relating to at least one of a forward link bandwidth configuration and a downlink bandwidth configuration.

27. The device of claim 19, wherein the at least one processor is adapted to determine the first resource based on data relating to at least one of a reverse link bandwidth configuration and an uplink bandwidth configuration.

28. The device of claim 19, wherein the at least one processor is adapted to determine the first resource based at least in part on at least one of sector ID data and system time data of the WAN AP.

29. The device of claim 19, wherein the at least one processor is adapted to assign by selecting the second resource based at least in part on a bandwidth portion that the WAN AT is expected to use to communicate with the WAN AP during a subsequent occurrence of an interlace.

30. The device of claim 19, wherein the at least one processor is adapted to assign by selecting an unjammed resource for the femto AT in response to at least one of the WAN AT and the WAN AP jamming at least one resource of the spectrum.

31. The device of claim 30, wherein the at least one processor is adapted to select by calculating a bandwidth portion that will be assigned to the WAN AT during a subsequent occurrence of an interlace, the unjammed resource comprising an available bandwidth portion other than the calculated bandwidth portion.

32. The device of claim 19, wherein the at least one processor is adapted to determine by inferring the first resource that is expected to be assigned to the WAN AT during a subsequent occurrence of an interlace based at least in part on the control message.

33. The device of claim 32, wherein the at least one processor is adapted to calculate whether co-assigning the first resource to the femto AT will increase a data transfer rate between the femto AT and a femto AP.

34. The device of claim 33, wherein the second resource comprises the first resource when it is calculated that co-assigning the first resource to the femto AT will increase the data transfer rate.

35. The device of claim 32, wherein the at least one processor is adapted to treat as erasure any data transferred on the first resource during the subsequent occurrence of the interlace, in response to determining that the data is unreliable.

36. The device of claim 35, wherein determining that the data is unreliable comprises determining that a signal energy level of the first resource exceeds a defined upper limit.

37. An apparatus for interference management in a spectrum shared by a WAN macro cell and a femto cell, comprising:

means for detecting a WAN access terminal (AT) in a coverage area of the femto cell;

means for accessing a control message sent by a WAN access point (AP) to the WAN AT;

means for determining a first resource of the spectrum that the WAN AT will use to communicate with the WAN AP based at least in part on the control message; and

means for assigning a second resource of the spectrum to a femto AT in the coverage area based at least in part on the determined first resource.

38. The apparatus of claim 37, wherein the means for accessing comprises means for intercepting the control message.

39. The apparatus of claim 38 wherein the means for accessing comprises means for receiving information from the WAN AT that facilitates intercepting the control message.

40. The apparatus of claim 39, wherein the received information comprises at least one of a Cell Radio Network Temporary Identifier (C-RNTI) and a Media Access Control Identifier (MAC ID).

41. The apparatus of claim 40, wherein the at least one of the C-RNTI and the MAC ID is sent from the WAN AP.

42. The apparatus of claim 37, wherein the control message comprises a broadcast message from the WAN AP.

43. The apparatus of claim 37, wherein the control message comprises at least one of an ACK message and a NACK message.

44. The apparatus of claim 37, wherein the means for determining comprises means for inferring the first resource based on data relating to at least one of a forward link bandwidth configuration and a downlink bandwidth configuration.

45. The apparatus of claim 37, wherein the means for determining comprises means for inferring the first resource based on data relating to at least one of a reverse link bandwidth configuration and an uplink bandwidth configuration.

46. The apparatus of claim 37, wherein the means for determining comprises means for inferring the first resource based at least in part on at least one of sector ID data and system time data of the WAN AP.

47. The apparatus of claim 37, wherein the means for determining comprises means for inferring a first bandwidth portion that the WAN AT will use to receive data from the WAN AP.

48. The apparatus of claim 37, wherein the means for determining comprises means for inferring a first bandwidth portion that the WAN AT will use to transmit data to the WAN AP.

49. The apparatus of claim 37, wherein the means for assigning comprises means for selecting a bandwidth portion that the WAN AT is expected to use to communicate with the WAN AP during a subsequent occurrence of an interlace.

50. The apparatus of claim 37, wherein the means for assigning comprises means for selecting an unjammed resource for the femto AT in response to at least one of the WAN AT and the WAN AP jamming at least one resource of the spectrum.

51. The apparatus of claim 37, wherein the means for selecting comprises means for calculating a bandwidth portion that will be assigned to the WAN AT during a subsequent occurrence of an interlace, the unjammed resource comprising an available bandwidth portion other than the calculated bandwidth portion.

52. The apparatus of claim 37, wherein the means for determining comprises means for inferring the first resource that is expected to be assigned to the WAN AT during a subsequent occurrence of an interlace based at least in part on the control message.

53. The apparatus of claim 52, wherein the means for determining comprises means for calculating whether co-assigning the first resource to the femto AT will increase a data transfer rate between the femto AT and a femto AP.

54. The apparatus of claim 53, wherein the second resource comprises the first resource when it is calculated that co-assigning the first resource to the femto AT will increase the data transfer rate.

55. The apparatus of claim 52, further comprising means for treating as erasure any data transferred on the first resource during the subsequent occurrence of the interlace, in response to determining that the data is unreliable.

56. The apparatus of claim 55, wherein determining that the data is unreliable comprises determining that a signal energy level of the first resource exceeds a defined upper limit.

57. A computer program product, comprising:

a non-transitory computer-readable median comprising;

code for causing a computer to detect a WAN access terminal (AT) in a coverage area of a femto cell that shares a spectrum with a WAN macro cell;

code for causing a computer to access a control message sent by a WAN access point (AP) to the WAN AT;

code for causing a computer to determine a first resource of the spectrum that the WAN AT will use to communicate with the WAN AP based at least in part on the control message; and

code for causing a computer to assign a second resource of the spectrum to a femto AT in the coverage area based at least in part on the determined first resource.

58. The computer program product of claim 57, wherein the non-transitory computer-readable medium further comprises code for causing a computer to intercept the control message.