White space sensing efforts

Hi everyone!

I’ve set up my USRP1 with 2 WBX, a dipole antenna - originally for FM
radio - connected to one WBX, and a 450 MHz omni antenna to the other
WBX. The connected PC is running Ubuntu 9.10 x86_64, build dependencies
for GNU Radio are installed, GNU Radio builds and runs fine.

Now what I’d like to do is implement sensing for white space devices[1],
entirely in free software, with hardware available from Ettus R…

To my knowledge, this is what has happened so far:

  • Microsoft presented a prototype to the FCC that was implemented using
    802.11 cards in combination with 2.4 GHz → UHF downconversion, and yes,
    they’re using the USRP and GNU Radio. [2]

  • Philips Research prestented a prototype to the FCC as well. Monisha
    Ghosh is going to present their most recent results regarding DVB-T
    sensing at DySpan 2010.

Is anybody else already working in this area?

The challenges are:

  • different TV/DTV standards in different regions (NTSC/ATSC in North
    America, PAL/SECAM/DVB-T in Europe, …)
  • wirless microphones also need to be detected (but that can be
    implemented later…)
  • sensing has to be reliable even below the noise floor (FCC requires
    -114 dBm, ETSI WG SE 43 is currently discussing the hidden node margin
    for Europe…)
  • we might have to circumvent or challenge patents or patent
    applications in this area

What I can offer:

  • time for coding bits and pieces needed for detection of incumbent
  • samples taken with my hardware
  • Eventually: remote access to my hardware, but that requires that we’ve
    physically met before. I need to trust you not to do something illegal
    with the WBX…

Some constraints I think are necessary for fairness:

  • all the results are shared, of course with proper credits given
  • all the results will be published under GPLv3 and copyright assigned
    to the FSF (or whatever is necessary to include it in GNU Radio trunk)

I’d like to collaborate with others instead of re-inventing the wheel

So far, we are already some folks over here in Europe who are working on
this … anybody else? Please speak up!



[1] White spaces (radio) - Wikipedia
[2] http://research.microsoft.com/apps/pubs/default.aspx?id=80952 (ACM
SIGCOMM Best Paper Award)

Hello Alex.

I know it has been awhile since you wrote this post, but I think I’m
currently in the phase that you were back then.

Any new directions? I have some simple results, but currently I’m trying
to do something more (transmission).

If you are willing to contribute, please let me know.