Penetration Testing mailing list archives

RE: Emulating a wireless access point


From: bparis () sorrentolactalis com
Date: Wed, 15 Aug 2001 12:42:41 -0400

        You are correct Meredith.

        I live near a cell tower (100m away) and can clearly hear cell
conversations on my scanner at the 1st lower harmonic, app 450-460Mhz.

        Getting back the the original question, cordless 2.4Ghz phones are
notorious for creating interference with other devices using the same freq
band. I recommend not operating 2.4Ghz phones in a wireless environment.

William S. Paris
Telecommunication/Network Analyst
Sorrento Lactalis Inc.
bparis () sorrentolactalis com


        Actually, it probably has to do w/ the frequency / harmonic
resonance of
the phone interfearing w/the AP ... not the proximity. Even if the phone
operates on a different frequency, it can interfere w/ the AP via harmonic
resonance.
        Harmonic Resonance occurs when one of the frequencies is a multiple
of the
other. Say your AP operates at 2 hz ( for simplicity sake) and your phone
operates at 4 hz, then every other cycle of the phones frequency will be in
phase w/ the access points.

ASCII Diagra:
|                  x -- sine peak                 As you can see, the sine
waves are prefectly
|      |   |   |   |                Phone         in-phase at 2 and 4 w/
respect to the phone.
|     | | | | | | | |
|        |   |   |   |
|_________________________________ T = 1 sec
|
|                      x -- sine peak
|          |       |
|     ....| |.....| |.               Access Point
|             | |
|              |
__________________________________ T = 1 sec

        Are there any Ham operators out there that can confirm or deny this?

 -- Meredith Shaebanyan

----------------------------------------------------------------------------
This list is provided by the SecurityFocus Security Intelligence Alert (SIA)
Service. For more information on SecurityFocus' SIA service which
automatically alerts you to the latest security vulnerabilities please see:
https://alerts.securityfocus.com/


Current thread: