RE: Questions regarding ath9k and new EN 300 328 regulation

["voncken" <cedric.voncken@acksys.fr>]

	Hi Adrien, 

	In the file driver/net/wireless/ath/dfs_pattern_detector.c a comment specify the dfs detector is compliant with EN300 328 1.5.1.
	Is it also compatible with E300 328 v1.8.1 ?

	Thanks for your reply.

	Cedric voncken.

> -----Message d'origine-----
> De : linux-wireless-owner@vger.kernel.org [mailto:linux-wireless-
> owner@vger.kernel.org] De la part de Adrien Decostre
> Envoyé : lundi 27 octobre 2014 19:24
> À : Zefir Kurtisi
> Cc : linux-wireless@vger.kernel.org; ath9k-devel@lists.ath9k.org
> Objet : Re: Questions regarding ath9k and new EN 300 328 regulation
> 
> Dear Zefir,
> 
> Thanks a lot for these precisions, This makes thing more clear.
> 
> There is still one thing unclear to me. If we do not consider working on the
> DFS channels and that we only want to operate on channels 36, 40, 44 and 48
> in EU. Do we still need to enable DFS flags in ath9k to comply with EN 300
> 328 v1.8.1. I mean, is the same pulse detector algorithm used for DFS and for
> the adaptivity tests on channels 36 to 48?
> 
> Many thanks in advance for your answer.
> 
> Best regards
> 
> Adrien
> 
> 
> On Mon, Oct 27, 2014 at 3:50 PM, Zefir Kurtisi <zefir.kurtisi@neratec.com>
> wrote:
> > On 10/27/2014 03:18 PM, Adrien Decostre wrote:
> >> Hello Zefir,
> >>
> >> Thanks a lot for your answer. This helps me a lot.
> >> If I correctly understand, the ability of ath9k to detect all pulses
> >> may also depend of the platform performances. So on an embedded
> >> platform with limited performances, we may observe more pulses losses
> >> than on a more powerful platform. Is this a right statement?
> >>
> > No, there is no bottleneck in the platform performance. Presumed radar
> > pulses are reported as RX_ERROR descriptors and even lower end
> > embedded systems are able to handle the load. What makes the
> > difference with the minimum pulse width is the chip DFS engine's
> > ability to isolate and identify very short spikes as potential radar
> pulses.
> >
> > This goes very deeply into material I had available under NDA while
> > implementing the DFS support for ath9k. If you intend to work on that
> > topic, I encourage you to contact the folks at QCA and join their 'NDA
> > for Developers' program. The document you want to read is 'Baseband DFS 2
> (Radar) Micro-Architecture'.
> >
> >> What about the CONFIG_ATH9K_DFS_CERTIFIED build options? Do we need
> >> it to enable the detection of 0.5usec. pulses?
> >>
> > Yes, this driver specific flag (also available for 10k) you need to
> > set to get the DFS detector built (not related to pulse width). It
> > essentially shifts the responsibility of the product working in restricted
> bands to you / the manufacturer.
> >
> >
> >> Thanks in advance for your answer.
> >>
> >> Best regards
> >>
> >> Adrien
> >>
> >
> > Good Luck,
> > Zefir
> --
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