Re: Emulating a wireless access point

From: Michael Boman (michaelat_private)
Date: Thu Aug 16 2001 - 02:48:12 PDT

  • Next message: Wyatt Fradenburg: "Wireless Security"

    On Tue, Aug 14, 2001 at 03:46:38PM -0700, Meredith S wrote:
    > 
    > 	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
    
    I am no Ham operator, but I read about this in school (studied
    electrioncs, HiFi system and so on). IIRC this is correct, a higher/lower
    frequency resonates every 1/2 of the currently frequency at half
    the effect.
    
    
    So lets say we are at 8 Hz originally, you will have your first
    set of "ghosts" at 4 rep. 12 Hz at half the original effect.  Second
    round of "ghosts" is at 2 and 14 Hz at a 1/4 of the original effect
    and so on...
    
    Again, it was over 5 years ago I studied or worked with this stuff.
    
    /Mike
    
    [rest of message truncated to save bandwith]
     
    -- 
    There is no such thing as a system that is secure out of the box.
    Tim [Timothy M. Mullen, CIO of AnchorIS.Com] claimed earlier this
    morning that he had found one at Val-Mart the other day that was
    secure out of the box, but as it turns out that was a Nintendo.
    
    -- Jesper M Johansson, Ph.D. Assistant Professor of Information
       Systems at Boston University - during a SANS audio broadcast
    
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