Interference classification with minimal or incomplete information

• US 9,130,871 B2
• Filed: 02/20/2014
• Issued: 09/08/2015
• Est. Priority Date: 01/29/2010
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Aruba Networks Incorporated (Hewlett-Packard Enterprise Company)
• Inventors: Ponnuswamy, Subburajan
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US14/185,845
• Publication Number:
  US 20140169432A1
• Time in Patent Office: 565 Days
• Field of Search: 375/224, 375/227, 375/228, 375/259, 375/260, 375/267, 375/316, 375/346, 375/377
• US Class Current: 1/1
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04L 27/06 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks

Abstract

Interference classification with minimal or incomplete information. Receivers in access points and in other network devices on a wireless digital network may be switched to a spectrum monitor mode in which they provide amplitude-versus-frequency information for a chosen part of the spectrum. This may be performed by performing a FFT or similar transform on the signals from the receiver. Receivers are calibrated with known interference sources in controlled environments to determine peaks, pulse frequency, bandwidth, and other identifying parameters of the interference source in best and worst case conditions. These calibrated values are used for matching interference signatures. Calibration is also performed using partial signatures collected over a short period in the order of microseconds. These partial signals may be used to detect interferers while scanning.

Claims

1. A non-transitory computer readable medium comprising instructions which, when executed by one or more hardware processors, causes performance of operations comprising:

calibrating the receiver and generating a library of signatures for the receiver,

receiving a signal at the receiver, and

classifying the signal by matching the signal to one or more signatures of the library of signatures.

2. The medium of claim 1 wherein the receiver includes a wireless radio and is switched between a first mode in which the receiver is used as part of a wireless access point and a second mode in which the receiver is used to classify signals.

3. The medium of claim 2 wherein the receiver is switched between the first mode and the second mode remaining on the same receive frequency.

4. The medium of claim 2 wherein the receiver is switched between the first mode on a first frequency and the second mode on a second frequency.

5. The medium of claim 1 wherein the receiver is part of a radio deployed within a dedicated monitoring device.

6. The medium of claim 1 wherein the receiver is part of a radio deployed within a wireless client device.

7. The method of claim 1 wherein the step of calibrating the receiver and generating a library of signatures comprises:

exposing the receiver to one or more known signal sources, and

recording a signature for the one or more known signal sources.

8. The medium of claim 7 wherein one of the known signal sources is a signal generator.

9. The medium of claim 7 wherein one of the known signal sources is a microwave oven.

10. The medium of claim 7 wherein one of the known signal sources is a frequency-hopping device.

11. The medium of claim 7 wherein the signature recorded is a partial signature.

12. The medium of claim 1 wherein the step of calibrating the receiver includes recording the variation of receiver noise floor in the presence of one or more signal sources and recording that variation in the signature.

13. The medium of claim 1 wherein the step of receiving a signal at the receiver further includes using an estimation algorithm to reconstruct incomplete signals.

14. The medium of claim 1 wherein the step of classifying the signal by matching the signal to one or more signatures of the library of signatures comprises:

matching the signal against a single signature.

15. The medium of claim 1 wherein the step of classifying the signal by matching the signal to one or more signatures of the library of signatures comprises:

matching the signal against a combination of signatures.

16. The medium of claim 1 wherein the step of classifying the signal by matching the signal to one or more signatures of the library of signatures comprises:

matching the signal against a combination of signatures of the same type.

17. The medium of claim 1 wherein the step of classifying the signal further includes detecting a signal on multiple channels.

18. The medium of claim 17 wherein the step of detecting a signal on multiple channels uses signature information containing hopping patterns of known frequency hopping devices.

19. The medium of claim 17 wherein the frequency hopping device is either a Bluetooth device or a cordless phone.

20. The medium of claim 1 wherein the library of signatures includes a plurality of interference signatures.