CHANNEL SELECTION TO REDUCE INTERFERENCE TO A WIRELESS LOCAL AREA NETWORK FROM A CELLULAR NETWORK

• US 20150063323A1
• Filed: 09/03/2014
• Published: 03/05/2015
• Est. Priority Date: 09/04/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: SADEK, Ahmed Kamel, TOKGOZ, Yeliz, YAVUZ, Mehmet, KADOUS, Tamer Adel, FAN, Mingxi, VALLIAPPAN, Nachiappan
• Granted Patent: US 10,979,203 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

The disclosure is related to selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell comprising a WLAN access point and a cellular network modem. The small cell performs a channel scan of available channels, determines whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold, and selects the clean channel as the operating channel for the cellular network based on the clean channel being available or turns off the cellular network based on no clean channel being available.

Claims

1. A method for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

performing, by the small cell, a channel scan of available channels, the small cell comprising a WLAN access point and a cellular network modem;

determining whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

selecting the clean channel as the operating channel for the cellular network based on the clean channel being available or turning off the cellular network based on no clean channel being available.

2. The method of claim 1, wherein the clean channel comprises a channel with a maximum beacon received signal strength indicator (RSSI) less than an RSSI threshold.

3. The method of claim 2, wherein the WLAN interference threshold comprises the RSSI threshold.

4. The method of claim 1, further comprising:

assigning a utility value to each available channel that has a maximum beacon RSSI less than an RSSI threshold, wherein the utility value is based on a noise floor and the maximum beacon RSSI.

5. The method of claim 4, wherein the selected operating channel comprises an available channel with a highest utility value.

6. The method of claim 1, further comprising:

performing the channel scan periodically or in response to an event.

7. The method of claim 6, wherein the event comprises detection, by the WLAN access point or a user device connected to the WLAN access point, of interference on the operating channel higher than a threshold.

8. The method of claim 1, further comprising:

determining whether or not channel switching criteria for switching to a new operating channel based on the channel scan have been met; and

switching to the new operating channel based on determining that the channel switching criteria have been met.

9. The method of claim 8, wherein the channel switching criteria comprise an indication of whether or not a beacon RSSI of a new beacon is greater than the threshold and/or an indication of whether there is a new channel with a higher utility value than the operating channel.

10. The method of claim 1, wherein the cellular network comprises a Long Term Evolution (LTE) network in unlicensed spectrum.

11. A method for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

performing, by a cellular network modem of the small cell, a first channel scan of available channels for operating the cellular network;

performing, by a WLAN access point of the small cell, a second channel scan of the available channels for operating the cellular network;

identifying, based on the first channel scan, one or more cellular network channels of the available channels that have an interference level below a cellular network interference threshold;

determining, based on the second channel scan, whether or not there is a clean channel in the identified one or more cellular network channels to be the operating channel for the cellular network, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

selecting the clean channel as the operating channel for the cellular network based on the clean channel being available or turning off the cellular network based on no clean channel being available.

12. The method of claim 11, wherein the clean channel comprises a channel with a maximum beacon received signal strength indicator (RSSI) less than an RSSI threshold.

13. The method of claim 12, wherein the WLAN interference threshold comprises the RSSI threshold.

14. The method of claim 11, further comprising:

assigning a utility value to each of the one or more channels that has a maximum beacon RSSI less than an RSSI threshold, wherein the utility value is based on a noise floor and the maximum beacon RSSI.

15. The method of claim 14, wherein the selected operating channel comprises an available channel with a highest utility value.

16. The method of claim 11, further comprising:

performing the first and second channel scans periodically or in response to an event.

17. The method of claim 16, wherein the event comprises detection, by the WLAN access point or a user device connected to the WLAN access point, of interference on the operating channel higher than a threshold.

18. The method of claim 11, further comprising:

determining whether or not channel switching criteria for switching to a new operating channel based on the second channel scan have been met; and

switching to the new operating channel based on determining that the channel switching criteria have been met.

19. The method of claim 18, wherein the channel switching criteria comprise an indication of whether or not a beacon RSSI of a new beacon is greater than the WLAN interference threshold and/or an indication of whether there is a new channel with a higher utility value than the operating channel.

20. The method of claim 11, wherein the cellular network comprises a Long Term Evolution (LTE) network in unlicensed spectrum.

21. The method of claim 11, further comprising:

based on no cellular network channel with an interference level below the cellular network interference threshold being available, filtering out unavailable cellular network channels.

22. The method of claim 21, wherein the filtering comprises:

performing a network listen to search for any cellular network signals with an interference level above the cellular network interference threshold that overlap with a scan period of the WLAN access point;

detecting an access point beacon miss in a given scan period of the WLAN access point;

determining whether the access point beacon miss is correlated to a presence of a cellular network signal; and

based on the access point beacon miss being correlated to a presence of a cellular network signal, maintaining a previous access point beacon RSSI for a cellular network channel corresponding to the cellular network signal until the interference level is not above the cellular network interference threshold.

23. The method of claim 21, wherein the filtering comprises:

generating a clean cellular network signal by performing successive interference cancellation on a cellular network signal with an interference level above the cellular network interference threshold; and

providing the clean cellular network signal to the WLAN access point.

24. The method of claim 23, wherein the clean cellular network signal comprises a waveform that does not include the cellular network signal with the interference level above the cellular network interference threshold and contains only residual WLAN access point signals for beacon detection.

25. The method of claim 23, wherein the performing the successive interference cancellation and the providing are performed by a user device in communication with the small cell.

26. The method of claim 23, wherein the performing the successive interference cancellation and the providing are performed by the small cell.

27. The method of claim 21, wherein the filtering comprises:

synchronizing channel scans of available WLAN access point channels among a plurality of small cells belonging to a same operator, the plurality of small cells including the small cell; and

muting the small cell to permit the WLAN access point to determine a current wireless environment of the small cell.

28. The method of claim 11, wherein the available channels comprise all cellular network channels available for operating the cellular network.

29. An apparatus for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

logic configured to perform, by the small cell, a channel scan of available channels, wherein the small cell comprises a WLAN access point and a cellular network modem;

logic configured to determine whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

logic configured to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.

30. The apparatus of claim 29, wherein the clean channel comprises a channel with a maximum beacon received signal strength indicator (RSSI) less than an RSSI threshold.

31. The apparatus of claim 30, wherein the WLAN interference threshold comprises the RSSI threshold.

32. The apparatus of claim 29, further comprising:

logic configured to assign a utility value to each available channel that has a maximum beacon RSSI less than an RSSI threshold, wherein the utility value is based on a noise floor and the maximum beacon RSSI.

33. The apparatus of claim 32, wherein the selected operating channel comprises an available channel with a highest utility value.

34. The apparatus of claim 29, further comprising:

logic configured to perform a channel scan periodically or in response to an event.

35. The apparatus of claim 34, wherein the event comprises detection, by the WLAN access point or a user device connected to the WLAN access point, of interference on the operating channel higher than a threshold.

36. The apparatus of claim 29, further comprising:

logic configured to determine whether or not channel switching criteria for switching to a new operating channel based on the channel scan have been met; and

logic configured to switch to the new operating channel based on determining that the channel switching criteria have been met.

37. The apparatus of claim 36, wherein the channel switching criteria comprise an indication of whether or not a beacon RSSI of a new beacon is greater than the threshold and/or an indication of whether there is a new channel with a higher utility value than the operating channel.

38. The apparatus of claim 29, wherein the cellular network comprises a Long Term Evolution (LTE) network in unlicensed spectrum.

39. An apparatus for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

logic configured to perform, by a cellular network modem of the small cell, a first channel scan of available channels for operating the cellular network;

logic configured to perform, by a WLAN access point of the small cell, a second channel scan of the available channels for operating the cellular network;

logic configured to identify, based on the first channel scan, one or more cellular network channels of the available channels that have an interference level below a cellular network interference threshold;

logic configured to determine, based on the second channel scan, whether or not there is a clean channel in the identified one or more cellular network channels to be the operating channel for the cellular network, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

logic configured to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.

40. The apparatus of claim 39, wherein the clean channel comprises a channel with a maximum beacon received signal strength indicator (RSSI) less than an RSSI threshold.

41. The apparatus of claim 40, wherein the WLAN interference threshold comprises the RSSI threshold.

42. The apparatus of claim 39, further comprising:

logic configured to assign a utility value to each of the one or more channels that has a maximum beacon RSSI less than an RSSI threshold, wherein the utility value is based on a noise floor and the maximum beacon RSSI.

43. The apparatus of claim 42, wherein the selected operating channel comprises an available channel with a highest utility value.

44. The apparatus of claim 39, further comprising:

logic configured to perform the first and second channel scans periodically or in response to an event.

45. The apparatus of claim 44, wherein the event comprises detection, by the WLAN access point or a user device connected to the WLAN access point, of interference on the operating channel higher than a threshold.

46. The apparatus of claim 39, further comprising:

logic configured to determine whether or not channel switching criteria for switching to a new operating channel based on the second channel scan have been met; and

logic configured to switch to the new operating channel based on determining that the channel switching criteria have been met.

47. The apparatus of claim 46, wherein the channel switching criteria comprise an indication of whether or not a beacon RSSI of a new beacon is greater than the WLAN interference threshold and/or an indication of whether there is a new channel with a higher utility value than the operating channel.

48. The apparatus of claim 39, wherein the cellular network comprises a Long Term Evolution (LTE) network in unlicensed spectrum.

49. The apparatus of claim 39, further comprising:

logic configured to filter out unavailable cellular network channels based on no cellular network channel with an interference level below the cellular network interference threshold being available.

50. The apparatus of claim 49, wherein the logic configured to filter comprises:

logic configured to performing a network listen to search for any cellular network signals with an interference level above the cellular network interference threshold that overlap with a scan period of the WLAN access point;

logic configured to detect an access point beacon miss in a given scan period of the WLAN access point;

logic configured to determine whether the access point beacon miss is correlated to a presence of a cellular network signal; and

logic configured to maintain, based on the access point beacon miss being correlated to a presence of a cellular network signal, a previous access point beacon RSSI for a cellular network channel corresponding to the cellular network signal until the interference level is not above the cellular network interference threshold.

51. The apparatus of claim 49, wherein the filtering comprises:

logic configured to generate a clean cellular network signal by performing successive interference cancellation on a cellular network signal with an interference level above the cellular network interference threshold; and

logic configured to provide the clean cellular network signal to the WLAN access point.

52. The apparatus of claim 51, wherein the clean cellular network signal comprises a waveform that does not include the cellular network signal with the interference level above the cellular network interference threshold and contains only residual WLAN access point signals for beacon detection.

53. The apparatus of claim 51, wherein performing the successive interference cancellation and the providing are performed by a user device in communication with the small cell.

54. The apparatus of claim 51, wherein performing the successive interference cancellation and the providing are performed by the small cell.

55. The apparatus of claim 49, wherein the logic configured to filter comprises:

logic configured to synchronize channel scans of available WLAN access point channels among a plurality of small cells belonging to a same operator, the plurality of small cells including the small cell; and

logic configured to mute the small cell to permit the WLAN access point to determine a current wireless environment of the small cell.

56. The apparatus of claim 39, wherein the available channels comprise all cellular network channels available for operating the cellular network.

57. A small cell base station capable of selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by the small cell base station, comprising:

a cellular network modem;

an WLAN access point configured to perform a channel scan of available channels; and

a processor configured to determine whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold, and to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.

58. A small cell base station capable of selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by the small cell base station, comprising:

a cellular network modem configured to perform a first channel scan of available channels for operating the cellular network;

a WLAN access point configured to perform a second channel scan of the available channels for operating the cellular network; and

a processor configured to identify, based on the first channel scan, one or more cellular network channels of the available channels that have an interference level below a cellular network interference threshold, to determine, based on the second channel scan, whether or not there is a clean channel in the identified one or more cellular network channels to be the operating channel for the cellular network, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold, and to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.

59. An apparatus for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

means for performing, by the small cell, a channel scan of available channels, the small cell comprising a WLAN access point and a cellular network modem;

means for determining whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

means for selecting the clean channel as the operating channel for the cellular network based on the clean channel being available or turning off the cellular network based on no clean channel being available.

60. An apparatus for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

means for performing, by a cellular network modem of the small cell, a first channel scan of available channels for operating the cellular network;

means for performing, by a WLAN access point of the small cell, a second channel scan of the available channels for operating the cellular network;

means for identifying, based on the first channel scan, one or more cellular network channels of the available channels that have an interference level below a cellular network interference threshold;

means for determining, based on the second channel scan, whether or not there is a clean channel in the identified one or more cellular network channels to be the operating channel for the cellular network, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

means for selecting the clean channel as the operating channel for the cellular network based on the clean channel being available or turning off the cellular network based on no clean channel being available.

61. A non-transitory computer-readable medium for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

at least one instruction to perform, by the small cell, a channel scan of available channels, wherein the small cell comprises a WLAN access point and a cellular network modem;

at least one instruction to determine whether or not there is a clean channel to be the operating channel for the cellular network based on the channel scan, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

at least one instruction to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.

62. A non-transitory computer-readable medium for selecting an operating channel for a cellular network to reduce interference to a wireless local area network (WLAN) operated by a small cell, comprising:

at least one instruction to perform, by a cellular network modem of the small cell, a first channel scan of available channels for operating the cellular network;

at least one instruction to perform, by a WLAN access point of the small cell, a second channel scan of the available channels for operating the cellular network;

at least one instruction to identify, based on the first channel scan, one or more cellular network channels of the available channels that have an interference level below a cellular network interference threshold;

at least one instruction to determine, based on the second channel scan, whether or not there is a clean channel in the identified one or more cellular network channels to be the operating channel for the cellular network, wherein a clean channel comprises a channel that interferes with the WLAN less than a WLAN interference threshold; and

at least one instruction to select the clean channel as the operating channel for the cellular network based on the clean channel being available or to turn off the cellular network based on no clean channel being available.