> -----Original Message----- > From: Eric Blossom [mailto:[EMAIL PROTECTED] > > On Wed, Dec 06, 2006 at 12:01:03AM -0500, Tom Rondeau wrote: > > 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 > > Actually, I think you should be able to detect Bluetooth without too > much trouble. If you just stare at a single point in the spectrum you > should be able to reliably detect 7 1 MHz channel's worth of data. > > IIRC the hopping sequence is known, and thus you should be able to > determine if what you are seeing is bluetooth or not, even though you > are seeing only 7 out of 79 channels. > > Eric
I was thinking that, too, but you'll just see short blips on the screen. Actually, if I get another second to breathe today, I'm going to see if I can make it happen and see what can be seen. Tom _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
