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CorteXlab Hackathon: Sniff n Stuff

Now that you have taken some control over our testbed and hopefully completed the tutorials, let's have some real challenge, more precisely a SDR challenge! Before we start, you have to do the following:

  • Form teams and give them cool names
  • Give us the infos (team names, members' names & emails)

Only after validating your team you will be able to access the challenge.

Why do we need your email? Well, the winning team members will receive a “Certificate of Success” after the conference.

To verify your progress, there will be several checkpoints to be validated by one of the organizers (Leo, Othmane). Be careful not to spill information to the other teams!!!

The groups

Each team will have a group number and thus have access to specific nodes following this table :

Group SSH login Nodes to use Port Assigned team 1st chk 2nd chk 3rd chk 4th chk
X tutoY node Z RadIO Riders
1 tuto1 node 3 6663 SpectrumShredders X X X
2 tuto2 node 4 6664 Stuck@StepOne X X X X
3 tuto3 node 7 6665 RadioTang X X X
4 tuto4 node 8 6666 SuperHeterodyne X X X
5 tuto5 node 6 6667 FakeRaDIO X
6 tuto6 node 23 6668
7 tuto7 node 27 6669
8 tuto8 node 24 6670
9 tuto9 node 28 6671

Refresh this page, when you see your team name assigned it means you can start the Hackathon !

Also refresh this page to see your progress and the progress of the other groups


  • SpectrumShredders: Pascal Girard et Matthieu Imbert
  • Stuck@StepOne: Yonathan Bleyfuesz
  • RadioTang: Tanguy Risset
  • SuperHeterodyne: Cyrille Morin
  • FakeRaDIO: Jean Marie Gorce

The Challenge

The goal of this Hackathon is to detect a signal in CorteXlab and understand its protocol then try to decode the useful data within it. So there is 3 main stages (i.e checkpoints)

Stage 1: The detection

There is an unknown signal emitted in CorteXlab somewhere between 800 MHz and 900 MHz. Use the tools you discovered throughout the tutorials, and Find it! Bear in mind that the USRP can sample a maximum of 20 MHz of band.

Remember that if you reach a checkpoint you have to tell us, otherwise if you reach the next checkpoint we will call it Fake News. Sad.

Stage 2: The protocol

Now that you have detected the unknown signal, it's time to understand its waveform.

Once you reach this stage we will provide you a GNU Radio receiver to help you store received signals. Tell us when you distinguish the signal components.

Hint : Plotting is understanding

Stage 3: The decoding

You figured out how the data is transmitted, didn't you ? Okay, now you have to extract the actual message from the waveform. The message contains the frequency in MHz for the bonus stage, for example, if you find the string “502” it means 502 MHz.

Adapt the receiver flow graph if you need to and transform data into something more human =)

Bonus stage: Fill in the blanks

Nice job getting here comrade. If you want to play a little bit more with CorteXlab, we set several transmitters. One will be transmitting at the frequency found in stage 3 and two others will be transmitting somewhere between 2 GHz and 2.1 GHz, if you succeed, you'll be able decode transmitted words and fill in the blanks in this sentence:

… will … the …

Final result

The final result will be displayed here:

1st place 2nd place 3rd place
Stuck@StepOne SpectrumShredders SuperHeterodyne

Special mention to team “SuperHeterodyne” for writing their own scanning GNU Radio code on the fly! It made them loose some time with respect to the others, but it was an elegant way to solve the problem. 8-)

hackathon.txt · Last modified: 2018/04/11 19:29 by lcardoso