not long ago it used to be exceedingly expensive to inspect and
process RF spectrum in detail, and the tools for such were both
cumbersome and limited.
i've been watching this trend change drastically over the last half
decade, fueled by a combination of pervasive high speed digital
networks and the DSP workhorses they require (OFDM is a computational
pig), and the general surge in interest around wireless communications
for commodity / broadband use.
to address the cost issue of intercepting and processing FHSS/DSSS in
the 900Mhz band, let me simply point to the GNU Radio USRP [0]. the
cost has gone up a bit from the original prototypes, but ~$600 for the
board and 900Mhz front ends is fairly cheap. this can intercept and
process FHSS/DSSS phone conversations with ease. #include
<std_disclaimer> : THIS IS ILLEGAL FOR YOU TO DO IN MOST SITUATIONS.
moving on toward the few thousand dollar price point you get to
nallatech gear, like their Virtex-4 Quad ADC unit [1] which combines
an FPGA for signal processing with FOUR very high rate 12-bit 250MSPS
ADC on board. you can get these boards on PCI/PCI-X [2] motherboards
for easy integration into a host system.
given the hardware above, GNU Radio and OpenCores.org [3] fill much of
the remaining work to utilize these systems for various purposes.
while a lot of this is "roll your own", it seems likely that the
market for integrated solutions built with flexible software defined
radios, and commodity signal processing components will be large.
(how much would you pay for an RF sweep unit that used a number of the
nallatech boards to scan in parallel what used to take dozens of
iterative setup/inspect/teardown steps? and had the software smarts to
discern irrelevant signals and highlight suspicious ones?)
i believe this will have some interesting and profound implications,
with hints of some of what is to come reflected in the open GSM
project and 802.11 work in GNU Radio.
a few years back active GSM interception and man-in-the-middle would
cost $50,000 in hardware. this price point is now down to a few
thousand dollars. it won't be long until effective privacy over
wireless (be it cordless phones, cell phones, wifi voip phones, etc)
requires strong ciphers and no less. some might argue we're at that
point already.
best regards,
0. GNU Radio Universal Software Radio Peripheral
http://www.comsec.com/wiki?UniversalSoftwareRadioPeripheral
1. Nallatech Virtex-4 Quad ADC DIME-II Module
http://www.nallatech.com/?node_id=1.2.2&id=31
2. PCI FPGA Computing Card w DIME Slot
http://www.nallatech.com/?node_id=1.2.2&id=6&tab=2
3. Open Cores Categories (see DSP, ECC, etc)
http://www.opencores.org/browse.cgi/by_category
Received on Sat Mar 02 2024 - 00:57:16 CST