At 06:43 PM 4/6/2003 -0700, Major Variola (ret) wrote:
At 03:53 AM 4/6/03 +0200, Thomas Shaddack wrote:
>Messing around TSCM.com, musing over detection of bugs. Getting an
>immediate idea I'd like to get peer-reviewed.
>
>There is a problem with bug sweeps in some countries. The legal TCSM
>providers can be legally required to not inform the client about a
>police-authorized bug, and/or legally forbidden to tamper with it. So a
>customer-operated solution should exist.
>
>GNU-Radio project seems to me to be flexible enough to be suitable as a
>bug detector.
Insufficient B/W. Look up "WinRadio".
I'm not too sure. If the bugs are using advanced transmission techniques,
like UWB, then you're right. But if they are only using standard
narrowband, frequency hopping or direct sequence you have some chance of
identifying a near field signal. The current implementation using a cable
modem down-converter, 'dumb' A/D board, with a dual-Athelon PC is capable
of simultaneously processing one or more complex signal waveforms (e.g.,
ATSC HDTV) in its 6 MHz pass band from 50 MHz - 860 MHz in real-time. The
A/D board can digitize at Msamples/sec, so it easily over-samples the 6MHz
down-converter's bandwidth. With an upcoming 'smart' A/D board 10MHz or
greater bandwidths may be achieved, with capability for dynamically
load-able firmware for correlators and on-board demodulation of complex
waveforms. Future version of the 'smart' A/D board may permit them to be
configured with their PC hosts as 'blades' in a larger comm. assembly for
true SIGINT style operation.
So, if you have one or more down-converters that can cover the spectrum of
interest and convert it down to a DC-6MHz IF, then a GNURadio system might
be useful for TCSM.
steve
steve
