System and method for management of a shared frequency band

• US 7,424,268 B2
• Filed: 04/22/2003
• Issued: 09/09/2008
• Est. Priority Date: 04/22/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Seed, William R., Diener, Neil R., Scholl, Thomas H., Miller, Karl A.
• Primary Examiner(s): Maung; Nay A.
• Assistant Examiner(s): Wendell; Andrew
• Application Number:
  US10/420,515
• Publication Number:
  US 20040028003A1
• Time in Patent Office: 1,967 Days
• Field of Search: 455/423, 455/515, 455/62, 455/67.11, 455/63.1, 455/67.13, 455/41.2, 370/241
• US Class Current: 455/62
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/1664 the supervisory signal being transmitted together with payload signals; piggybacking
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

A system, method, software and related functions are provided for managing activity in a radio frequency band that is shared, both in frequency and time, by signals of multiple types. An example of such a frequency band is an unlicensed frequency band. Radio frequency energy in the frequency band is captured at one or more devices and/or locations in a region where activity in the frequency band is happening. Signals occurring in the frequency band are detected by sampling part or the entire frequency band for time intervals. Signal pulse energy in the band is detected and is used to classify signals according to signal type. Using knowledge of the types of signals occurring in the frequency band and other spectrum activity related statistics (referred to as spectrum intelligence), actions can be taken in a device or network of devices to avoid interfering with other signals, and in general to optimize simultaneous use of the frequency band with the other signals. The spectrum intelligence may be used to suggest actions to a device user or network administrator, or to automatically invoke actions in a device or network of devices to maintain desirable performance.

Claims

1. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said classifying determines that the interfering signal is a known signal type and is a signal associated with another WLAN operating on a channel that is adjacent to a channel of the WLAN on which said device is operating, said generating comprises generating a recommended action comprising one or more of;

adjusting the location of said other WLAN, and adjusting a location of the access point for the WLAN on which said device operates.

2. The method of claim 1, wherein monitoring comprises receiving radio frequency energy in substantially the entire frequency band for a time interval.

3. The method of claim 1, wherein monitoring comprises receiving radio frequency energy in a portion of the radio frequency band.

4. The method of claim 3, wherein monitoring further comprises scanning across the frequency band to receive radio frequency energy in different portions of the radio frequency band.

5. The method of claim 1, wherein monitoring comprises monitoring activity obtained at different locations of a region associated with activity in the radio frequency band.

6. The method of claim 1, wherein monitoring comprises generating power spectral information associated with radio frequency energy received in the radio frequency band during time intervals.

7. The method of claim 6, and further comprising generating signal pulse information describing characteristics of pulses of radio frequency energy detected in the radio frequency band from the power spectral information.

8. The method of claim 6, wherein generating signal pulse information comprises generating signal pulse data including one or more of:

pulse duration, pulse center frequency, pulse bandwidth and time interval between pulses, for signal pulses detected in the frequency band from the spectrum activity information.

9. The method of claim 8, and further comprising accumulating signal pulse data for signal pulses detected over time in the frequency band.

10. The method of claim 9, and further comprising classifying signals in the frequency band based on accumulated signal pulse data, wherein generating is based on types of signals determined to be occurring in the frequency band.

11. The method of claim 1, and further comprising displaying information pertaining to characteristics of the classified signal.

12. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said classifying determines that the interfering signal is a known signal type and is a signal produced by operation of a microwave oven or similar appliance, said generating comprises generating a recommended action comprising one or more of;

adjusting the location of the access point of the WLAN on which said device operates, and increasing a distance between said device and said microwave oven.

13. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said classifying determines that the interfering signal is a known signal type and is a signal produced by a short-range frequency hopping device, further comprising notifying a user of said device that interference is being caused by a short-range frequency hopping device, and said generating comprises generating a recommended action comprising increasing a distance between said device and the short-range frequency hopping device.

14. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said classifying determines that the interfering signal is a known signal type and is a signal produced by a cordless phone, further comprising notifying a user of said device that a cordless phone causes interference to said WLAN and that the cordless phone be positioned at least a certain distance from said device or from an access point of said WLAN, and wherein generating comprises generating a recommended action comprising increasing distance between a base unit of the cordless phone and said device.

15. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said classifying determines that the interfering signal is an unknown type, said generating recommendation information comprises generating a recommended action comprising one or more of;

instructions to the user to check for recently acquired wireless equipment, increase the distance between the WLAN and any other incompatible wireless network, and an advisory to the user concerning potential wireless network incompatibility.

16. A method for managing use of a radio frequency band in which wireless signals of multiple types may occur, comprising:

monitoring radio frequency energy in a radio frequency band in which activity associated with a plurality of wireless signal types may occur to generate spectrum activity information representing activity in the frequency band;

determining when there is a degradation of performance of a device operating in the radio frequency band;

determining when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information;

classifying the interfering signal based on the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering signal is a known and otherwise to determine that the interfering signal is an unknown type;

generating recommendation information to a user to avoid the degradation in performance of the device caused by the interfering signal, wherein generating the recommendation information comprises generating at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type determined by said classifying;

wherein said device is operating in the frequency band on a wireless local area network and further comprising determining when the degradation of performance is caused by a low signal level, and wherein generating comprises generating a recommended action comprising one or more of;

adjusting antennas on said device, and adjusting a location of said device.

17. The method of claim 16, wherein generating information comprises generating recommendation information to instruct a user to make adjustments to the device or its environment to improve the received signal level.

18. The method of claim 16, wherein said device is operating in the frequency band on a wireless local area network (WLAN), said generating comprises generating a recommended action comprising one or more of:

adjusting a location of an access point of said WLAN, adjusting an antenna of the access point of said WLAN.

19. The method of claim 18, wherein generating comprises generating a recommended action comprising one or more of:

reducing obstructions between said device and said access point, and reducing a distance between said device and said access point.

20. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said computing device determines that the interfering signal is a known signal type and is a signal associated with another WLAN operating on a channel that is adjacent to a channel of the WLAN on which said device is operating, said computing device generates a recommended action comprising one or more of;

adjusting the location of said other WLAN, and adjusting a location of the access point for the WLAN on which said device operates.

21. The system of claim 20, wherein the radio device is coupled to the computing device by a wireless link or a wired link.

22. The system of claim 20, and further comprising a display coupled to the computing device, wherein the computing device displays the recommendation information.

23. The system of claim 20, and further comprising a wireless access point associated with one or more wireless network client stations.

24. The system of claim 23, wherein the computing device is coupled to the wireless access point and controls one or more operating parameters of the access point.

25. The system of claim 20, wherein the radio device comprises a radio receiver and a spectrum analyzer coupled to the radio receiver that performs spectral analysis of radio frequency energy received in the frequency band by the radio receiver to produce power spectral information of the received radio frequency energy.

26. The system of claim 25, wherein the radio receiver is capable of receiving signals across substantially the entire radio frequency band.

27. The system of claim 25, wherein the radio receiver is capable of receiving signals across a portion of the radio frequency band, and being controlled to tune to different portions of the radio frequency band.

28. The system of claim 25, wherein the radio device further comprises a signal detector coupled to the spectrum analyzer that detects signal pulses that have one or more characteristics from the power spectral information.

29. The system of claim 28, wherein the signal detector generates signal pulse data for signal pulses of pulses of radio frequency energy that are determined to have one or more characteristics that fall into corresponding one or more ranges.

30. The system of claim 29, wherein the radio device outputs for each signal pulse detected by the signal detector, signal pulse data comprising data selected from the group consisting of:

power level, center frequency, bandwidth, start time and duration.

31. The system of claim 30, wherein the computing device accumulates signal pulse data for signal pulses detected over time in the frequency band.

32. The system of claim 20, wherein the computing device generates a control signal to deny transmission of signals by a device in the frequency band when the spectrum activity information indicates a radar signal is present in the frequency band.

33. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said computing device determines that the interfering signal is a known signal type and is a signal produced by operation of a microwave oven or similar appliance, said computing device generates a recommended action comprising one or more of;

adjusting the location of the access point of the WLAN on which said device operates, and increasing a distance between said device and said microwave oven.

34. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said computing device determines that the interfering signal is a known signal type and is a signal produced by a short-range frequency hopping device, said computing device notifies a user of said device that interference is being caused by a short-range frequency hopping device, and said computing device generates a recommended action comprising increasing a distance between said device and the short-range frequency hopping device.

35. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said computing device determines that the interfering signal is a known signal type and is a signal produced by a cordless phone, said computing device notifies a user of said device that a cordless phone causes interference to said WLAN and that the cordless phone be positioned at least a certain distance from said device or from an access point of said WLAN, and said computing device generates a recommended action comprising increasing distance between a base unit of the cordless phone and said device.

36. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network (WLAN) and when said computing device determines that the interfering signal is an unknown type, said computing device generates a recommended action comprising one or more of;

instructions to the user to check for recently acquired wireless equipment, increase the distance between the WLAN and any other incompatible wireless network, and an advisory to the user concerning potential wireless network incompatibility.

37. A system for managing use of a radio frequency band in which wireless signals of multiple types may be present, comprising:

(a) a radio device that receives radio frequency energy in the radio frequency band to monitor activity of multiple types of wireless signals that may occur in the radio frequency band and generates spectrum activity information representative thereof; and

(b) a computing device coupled to the radio device that receives the spectrum activity information and generates at least one of;

a control for controlling a device operating in the radio frequency band, and information describing a particular type of activity determined to occur in the radio frequency band, wherein the computing device determines when there is a degradation of performance of a device operating in the radio frequency band and when the degradation of performance is caused by an interfering signal occurring in the frequency band based on the spectrum activity information, wherein the computing device classifies the interfering signal using the spectrum activity information to determine a signal type of the interfering signal if the signal type of the interfering is known and otherwise to determine that the interfering signal is an unknown type, and wherein the computing device generates recommendation information to instruct a user to avoid degradation in the performance of the device caused by the interfering signal, wherein the recommendation information comprises at least one recommended action that is presented to the user and wherein the recommended action depends on whether the interfering signal is a known signal type or is an unknown signal type;

wherein said device is operating in the frequency band on a wireless local area network and wherein said computing device further determines when the degradation of performance is caused by a low signal level, generates a recommended action comprising one or more of;

adjusting antennas on said device, and adjusting a location of said device.

38. The system of claim 37, wherein said device is operating in the frequency band on a wireless local area network (WLAN), and said computing device generates a recommended action comprising one or more of:

adjusting a location of an access point of said WLAN, adjusting an antenna of the access point of said WLAN.

39. The system of claim 38, wherein said computing device generates a recommended action comprising one or more of:

reducing obstructions between said device and said access point, and reducing a distance between said device and said access point.