I managed to find an old document that details the output from the driver and the pulses I generated.
I tried it with 2 different pulse characteristics : - Pulse width of 15 μs and PRF equal to 1000 Hz - Pulse width of 15 μs and PRF equal to 3000 Hz Image below details the second signal (PRF = 3kHz). [image: Images intégrées 1] This is some log when detecting the first signal [image: Images intégrées 2] This is some log when detecting the second signal [image: Images intégrées 3] You can see the driver recognizes the PRF quite well. I hope this helps a bit, Jawad 2016-01-08 23:13 GMT+01:00 Jawad Seddar <jawad.sed...@gmail.com>: > Hi Ralph, > > I did this 2 and half years ago and I basically followed the directions in > pages 60-61 of the ETSI document linked by Marcus to generate the signals. > > By watching the channel on which the WiFi card was operating, I generated > the signal at the right frequency and I could see the card changing > frequencies. I could then access some log files that detailed why the > frequency change happened (In this case it was saying that it had detected > a radar with a given Pulse Repetition Frequency and gave some details about > the detected signal). > > I believe I was using the ath5k drivers (see madwifi-project). > > Regards, > Jawad > > 2016-01-08 22:56 GMT+01:00 Marcus Müller <marcus.muel...@ettus.com>: > >> Hi Ralph, >> >> hm; depends, I think. >> >> So, there's two things: >> If you're referring to a channel switch announcement, that can be part >> of a management frame [1]. But I think it can also be part of a beacon >> frame. Or a probe response frame. >> Luckily, 802.11 is not confusing the least. >> Blind guess is that you should look into airprobe-ng's "aireplay" >> program and see whether it can synthesize such a frame. Basically, you >> should be able to forge at least beacon frames, which might be helpful >> as soon as you deauthenticated a station; a very common attack. >> >> More likely, even, is that you're talking about mimicking a fake radar. >> I guess the appropriate way to do that is probably sending something >> that looks sufficiently close enough to a chirp to the OFDM demod, I >> think. >> I'm too lazy to read this myself :D, so go and read 5.3.8.1 and >> following of ETSI EN 301 893 [2], and refer to a trustworthy free and >> open WiFi card driver (hint hint: atheros 9k, dfs_pattern_detector.c). >> >> Best regards, >> Marcus >> >> [1] >> >> https://mentor.ieee.org/802.11/dcn/10/11-10-0097-06-00ae-management-frame-analysis.xls >> [2] >> >> https://www.etsi.org/deliver/etsi_en/301800_301899/301893/01.05.01_60/en_301893v010501p.pdf >> >> On 08.01.2016 21:47, Ralph A. Schmid, dk5ras wrote: >> > Hi, >> > >> > Does anybody know how a signal must look to trigger a 5 GHz WLAN for a >> > frequency change? I intend testing this feature by transmitting a >> radar-like >> > signal with gnuradio, but for this I should know how this detection >> works, >> > how such a signal does look :) >> > >> > Ralph. >> > >> > >> > _______________________________________________ >> > Discuss-gnuradio mailing list >> > Discuss-gnuradio@gnu.org >> > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> _______________________________________________ >> Discuss-gnuradio mailing list >> Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > >
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