On 10/22/2016 07:49 AM, Sebastian Gottschall wrote:
atheros has a continues transmission mode which is used for power calibration 
in factory using the ART utility. its available on ath9k cards as well.
once enabled no wifi connection is possible on the same frequency since it will 
break up all CSMA handling also with neighbor networks. its a nice
feature for disconnecting all wifi networks in your area
look for the called atheros / qca TESTMODE. its a simple register setting 
(enable, disable)


I noticed recently that the carl9170 based system I was using can do a minimum
burst width of about 17us, which is not good enough for most RADAR emulation
settings (which often need 1us, 11us, etc).

So, I am back to thinking about trying this for ath9k, in hopes it can cycle
TX on/off faster.

So far, I have not found any useful info searching for TESTMODE in ath9k and 
madwifi code.

Do you have any more specific details about where I can find documents or source
code that uses the TX100 mode for ath9k?


Am 15.09.2016 um 17:28 schrieb Zefir Kurtisi:
Hi Ben,

On 09/15/2016 02:22 AM, Ben Greear wrote:
On 08/20/2015 08:11 AM, Zefir Kurtisi wrote:
On 08/19/2015 09:07 PM, Ben Greear wrote:
I have a commercial AP that is using a CM9 ath5k radio (evidently, I could be
and it has the ability to do a constant transmit of raw noise (RF probe shows
noise, but a monitor-port sniffer does not see any frames from the CM9).

I don't know the low-level details of how it is doing this, but I suspect
it is using something like madwifi for a driver.

Does anyone know how this can be done with modern software and
ath5k or ath9k NICs?


Maybe slightly related: some years ago when DFS became a topic and it was hard 
get hands on radar pattern generators, Christian Lamparter wrote a variant of 
carl9170 fw [1] which can generate radar pulses to test ath9k and other DFS 
detectors. Pulses are generated by enabling txout at defined sampling intervals.

It should be doable to mimic what you are looking for by generating a _very_ 
Sorry to revive such an old thread..but I'm back poking at this.

Whew, that year went by so incredibly fast ;)

I've used the modified carl9170 firmware to generate pulses, with
the control being 'pulse-width' and 'pulse-interval'.

This sort of works, and sometimes our ath10k in an isolation chamber reports
a radar event.

But, after some reading, I am thinking I need more control to better mimic
a radar.

If I understand things properly, I need something like this:

A pulse event being:  pulse width, pulse period:  For instance 1us, 200us
Then, I need to configure an amount of pulse events, maybe 10-30 consecutive 
Then, I need a quiet period to mimic the radar sweeping full circle (15 seconds

 From what I can tell, the carl9170 modified firmware is missing the features
to do this, though it should not be too difficult to add.

Yes, that's essentially it - the last step is even not needed if your goal is to
estimate DFS detection probabilities, since in the certification lab they 
just repeatedly fire the radar pattern and count detection events.

When I played with the modified carl9170 FW, I estimated that developing an 
and reliable radar pattern pulse scheduler would take me 2-4 weeks, so being in 
hurry I ended up using an SDR (Ettus USRP N200, see [1]). I developed a pulse
scheduler to feed arbitrary patterns (covering those for DFS testing), which is
available in [2]. It has not been maintained ever since, but might help you as
starting point if you decide to go that route.

If someone has an idea whether the control above is appropriate, I'd
appreciate feedback before I start hacking...

This document seemed useful, for instance:


We use the R&S SMBV100A [3], which we know is also used in some certification
labs. Unfortunately it is not exactly cheap - if you are not going to prepare 
product for certification, the SDR approach is affordable and good enough.


Good luck,

[1] https://www.ettus.com/product/details/UN200-KIT
[2] https://github.com/zefir-kurtisi/USRP-Radar-Relay

Ben Greear <gree...@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

Reply via email to