Method and apparatus for detecting the presence of a wireless network

• US 7,010,298 B2
• Filed: 05/22/2003
• Issued: 03/07/2006
• Est. Priority Date: 05/24/2002
• Status: Expired due to Fees

• Current Assignee: Chrysalis California LLC
• Original Assignee: Chrysalis California LLC
• Inventors: Seedman, Michael, Marchevsky, Bruno, Padgitt, David Gary
• Primary Examiner(s): GELIN, JEAN ALLAND
• Application Number:
  US10/443,639
• Publication Number:
  US 20040132446A1
• Time in Patent Office: 1,020 Days
• Field of Search: 455/421, 455/422.1, 455/432, 455/426.2, 455436-444, 455/307, 455/200, 455/434, 455/552.1, 455/553, 455/435.2, 455/161.1, 370/328, 370/331, 370/338, 370351-356, 370/401, 370/489, 370/349
• US Class Current: 455/434
• CPC Class Codes: H04B 17/20 of receivers
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A system and method for detecting the presence of a wireless LAN. The system includes a radio frequency receiver for receiving radio frequency signals and a controller having associated programming for controlling the receiver. The programming also functions to measure and analyze the energy of the received radio frequency signals for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device.

Claims

1. An apparatus for detecting the presence of a wireless Local Area Network (LAN) comprising:

a radio frequency receiver for receiving radio frequency signals; and

a controller having associated programming for controlling the receiver and measuring and analyzing the energy of the received radio frequency signals for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device;

wherein the programming functions to cause the apparatus to generally scan outside of a wireless LAN band to identify radio frequency signals outside of the wireless LAN band being generated by the noise generating electronic device also generating radio frequency signals inside the wireless LAN band.

2. The apparatus of claim 1, wherein the programming that functions to cause the apparatus to scan outside of the wireless LAN band functions to cause the apparatus to scan (i) frequencies lower than frequencies of the wireless LAN band, and (ii) frequencies greater than the frequencies of the wireless LAN band.

3. The apparatus of claim 2, wherein the wireless LAN band includes an 802.11 wireless network band.

4. The apparatus of claim 1, wherein the programming that functions to cause the apparatus to scan outside of the wireless LAN band functions to cause the apparatus to scan from a first frequency that is lower than the lowest frequency of the wireless LAN band to a second frequency that is greater than the greatest frequency of the wireless LAN band.

5. An apparatus for detecting the presence of a wireless Local Area Network (LAN) comprising:

a radio frequency receiver for receiving radio frequency signals; and

a controller having associated programming for controlling the receiver and measuring and analyzing the energy of the received radio frequency signals for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device;

wherein the programming functions to (i) cause the apparatus to scan a substantial entirety of a wireless LAN band to determine an overall energy level over time, and (ii) determine the wireless LAN is present if the overall energy level exceeds a threshold and is substantially constant over the time.

6. The apparatus as recited in claim 5, wherein the programming functions to examine the overall energy level over time and, when the overall energy level exceeds a predefined threshold, the programming deems the radio frequency signals as originating from the wireless LAN.

7. The apparatus of claim 5, wherein the apparatus scans the substantial entirety of the wireless LAN band in incremental steps.

8. The apparatus of claim 7, wherein the incremental steps are 2 MHz steps.

9. The apparatus of claim 5,

wherein the wireless LAN band includes an 802.11 wireless network band, and

wherein the overall energy level is substantially constant over the time if the energy level is contained within one 802.11 channel of the 802.11 wireless network band.

10. A method for detecting the presence of a wireless Local Area Network (LAN), comprising:

receiving radio frequency signals;

measuring the energy level of the received radio signals;

analyzing the measured energy levels for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device; and

generally scanning outside of a wireless LAN band to identify radio frequency signals outside of the wireless LAN band being generated by the noise generating electronic device also generating radio frequency signals inside the wireless LAN band.

11. The method of claim 10, wherein scanning outside of the wireless LAN band includes scanning (i) frequencies lower than frequencies of the wireless LAN band, and (ii) frequencies greater than the frequencies of the wireless LAN band.

12. The method of claim 11, wherein the wireless LAN band includes an 802.11 wireless network band.

13. The method of claim 10, wherein scanning outside of the wireless LAN band includes scanning from a first frequency that is lower than the lowest frequency of the wireless LAN band to a second frequency that is greater than the greatest frequency of the wireless LAN band.

14. A method for detecting the presence of a wireless Local Area Network (LAN), comprising:

receiving radio frequency signals;

measuring the energy level of the received radio signals;

analyzing the measured energy levels for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device;

scanning a substantial entirety of a wireless LAN band to determine an overall energy level over time, and

determining the wireless LAN is present if the overall energy level exceeds a threshold and is substantially constant over the time.

15. The method as recited in claim 14, further comprising the step of examining the overall energy level over time and, when the overall energy level exceeds a predefined threshold, deeming the radio frequency signals as originating from a wireless LAN.

16. The method of claim 14, wherein scanning the substantial entirety of the wireless LAN band comprises scanning the wireless LAN band in incremental steps.

17. The method of claims 16, wherein the incremental steps are 2 MHz steps.

18. The method of claim 14,

wherein the wireless LAN band includes an 802.11 wireless network band, and

wherein determining the overall energy level is substantially constant over the time comprises determining the energy level is contained within one 802.11 channel of the 802.11 wireless network band.

19. In a handheld device, a readable medium having instructions for detecting the presence of a wireless Local Area Network (LAN), the instructions performing steps comprising:

receiving radio frequency signals;

measuring the energy level of the received radio signals;

analyzing the measured energy levels for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device; and

generally scanning outside of a wireless LAN band to identify radio frequency signals outside of the wireless LAN band being generated by the noise generating electronic device also generating radio frequency signals inside the wireless LAN band.

20. The readable medium of claim 19, wherein scanning outside of the wireless LAN band includes scanning (i) frequencies lower than frequencies of the wireless LAN band, and (ii) frequencies greater than the frequencies of the wireless LAN band.

21. The readable medium of claim 20, wherein the wireless LAN band includes an 802.11 wireless network band.

22. The readable medium of claim 19, wherein scanning outside of the wireless LAN band includes scanning from a first frequency that is lower than the lowest frequency of the wireless LAN band to a second frequency that is greater than the greatest frequency of the wireless LAN band.

23. In a handheld device, a readable medium having instructions for detecting the presence of a wireless Local Area Network (LAN), the instructions performing steps comprising:

receiving radio frequency signals;

measuring the energy level of the received radio signals;

analyzing the measured energy levels for the purpose of determining if the radio frequency signals indicate the presence of a wireless LAN or are being produced by a noise generating electronic device;

scanning a substantial entirety of a wireless LAN band to determine an overall energy level over time, and

determining the wireless LAN is present if the overall energy level exceeds a threshold and is substantially constant over the time.

24. The readable media as recited in claim 23, wherein the instructions perform the further step of examining the overall energy level over time and, when the overall energy level exceeds a predefined threshold, deeming the radio frequency signals as originating from a wireless LAN.

25. The readable medium of claim 23, wherein scanning the substantial entirety of the wireless LAN band comprises scanning the wireless LAN band in incremental steps.

26. The readable medium of claim 25, wherein the incremental steps are 2 MHz steps.

27. The readable medium of claim 23,

wherein the wireless LAN band includes an 802.11 wireless network band, and

wherein determining the overall energy level is substantially constant over the time comprises determining the energy level is contained within one 802.11 channel of the 802.11 wireless network band.