In the last year or so there's been a fair amount of coverage of the excellent Ubertooth project.
Ubertooth One is an open source 2.4 GHz experimentation device, designed for messing with bluetooth, but with a lot of flexibility which gives rise some other very cool features, like spectrum monitoring.
Spectrum-Tools is available via apt, but as is often the case, the available version is too old to have Ubertooth support.
So, first off, let's install a recent version of the Spectrum-Tools. Running
svn co https://www.kismetwireless.net/code/svn/tools/spectools
Will grab the latest version of the source code from Kismet's subversion repository. Next, check the README, for information on dependencies, and install them. On BT5, I ran:
apt-get install libgtk2.0-dev libusb-dev
On Debian-based systems you'll probably need to prefix that with
sudo. You'll also need a working build environment, so run:
apt-get install build-essential
To install a pretty useful meta-package containing most build tools you're likely to need.
cd into the
spectools directory, then type go through the standard (ageless) build process, of:
./configure make make install
To build and install the software. On my BT5 system, the final command installed the binaries into
/usr/local, which seems to be where most of backtrack's special software ends up.
Now that you have Spectrum-Tools installed, it's time to play. The prettiest
thing to play with is
spectool_gtk, so plug your Ubertooth in, fire it up,
Open Device. Next, click
Enable, and you should be good to go.
If everything worked, you'll see a colourful interface, with three horizontal panes, showing three different representations of the spectrum, with WiFi channels at the bottom.
The README file has more information on these different views, but I think the most interesting is the Spectral View, as you can clearly see frequency hopping devices as bright spots:
If you're trying to decide on a channel to use for you wireless network, you'll probably find the Planar View most useful. This is a more traditional spectrum, and clearly shows how the channels are utilised. The Topo View shows signal peaks over time, and gives similar information to the Planar View:
Right clicking on these two graphs lets you toggle a few options. If your Planar View, is looks too busy, for example, it can be useful to switch of the current values.
The Planar View also supports markers, and can show channel masks. Markers aren't very well documented (and so this took me a while to work out!). To active markers, click on an entry in the table on the right, and then drag on the planar view to drop the marker. To show a channel's mask, click on the channel number on the legend: