[Discuss-gnuradio] 802.11 and Bluetooth

[Tom Rondeau]

I've seen a number of questions about these issues in the past couple of
days, so I'm addressing this from my own knowledge.

Can we detect Bluetooth and WiFi with GNU Radio?

I'm making two assumptions: we're using the USRP and WiFi/802.11 is
specifically addressing 802.11a/b/g.

The answer is no. The bandwidth is too large for the system to currently
handle. If you tune the GNU Radio to the center frequency of an 802.11
channel, you'll see what looks like a rise in the noise floor (and, under
these conditions, it really is a rise in the noise) when there is a
transmission.

Bluetooth signals hop from 2.402 - 2.480 MHz; 79 1 MHz channels at a rate of
1600 hops per second. The GNU Radio cannot look a the entire band all at
once, so if you look at a particular slice (~4 MHz) of spectrum, you might
catch a glimpse of a signal every now and then, unless you can plug in the
right frequency hopping sequence (I think I have both MATLAB and C++ code to
do this, buried somewhere, but then you'd need the master address (easy) and
its clock (difficult) to do it; and I'm not sure if the USRP's can change
frequency and settle fast enough for this).

If you have some 1 or 2 Mbps 802.11 devices to use, the BBN guys have done
work on receiving those (search the list, it's been addressed a number of
times in the past).

Hope this clears a bit up,
Tom