RE: DFS ETSI conformance for weather channels (again) - Jean-Pierre Tosoni

From: "Jean-Pierre Tosoni" <jp.tosoni@acksys.fr>
To: "'Kalle Valo'" <kvalo@codeaurora.org>
Cc: <linux-wireless@vger.kernel.org>
Subject: RE: DFS ETSI conformance for weather channels (again)
Date: Thu, 26 Mar 2015 18:02:20 +0100	[thread overview]
Message-ID: <000901d067e6$9f471840$ddd548c0$@acksys.fr> (raw)
In-Reply-To: <87619nagm4.fsf@kamboji.qca.qualcomm.com>

Thanks Kalle,

I will check the wireless-regdb list instead.
But it looks like the current python script that generates regulatory.bin
was not updated for CAC time yet :-(

Cheers,
Jean-Pierre

-----Message d'origine-----
De : Kalle Valo [mailto:kvalo@codeaurora.org] 
Envoyé : jeudi 26 mars 2015 17:06
À : Jean-Pierre TOSONI
Cc : linux-wireless@vger.kernel.org
Objet : Re: DFS ETSI conformance for weather channels (again)

"Jean-Pierre TOSONI" <jp.tosoni@acksys.fr> writes:

> Hi list,
>
> I just stumbled on this patch that IMHO was rejected for a bad reason:
>
>   [PATCH v3 4/4] cfg80211: DFS use 10 minutes CAC when weather channels
>   At http://www.spinics.net/lists/linux-wireless/msg115296.html
>
> The reason given is the "unachievable" requirement in the ETSI norm of 
> 99.99% detection success. It was even considered disabling the weather 
> channels.
>
> *But the norm (ETSI EN 301 893 V1.7.1) does not say this.* It states 
> that 99.99% is the target performance:
>
>  - during conformance tests only, (5.3.8.1.1 paragraph 5)
>  - specifically *not* a requirement with specific real life radars,
> (5.3.8.1.1 paragraph 5)
>  - on a limited series of 20 tests, (5.3.8.2.1.2 item g)
>  - with a pulse power at +10dB above other pulse detection tests,
> (5.3.8.2.1.2 item f)
>  - with some patterns excluded from the test. (5.3.8.2.1.2 item g)
>
> Hence it is very possible that existing products can achieve the 
> conformance test target.
>
> That being said, would it be possible to reexamine that dropped patch 
> and apply it?

Don't we support this by getting the CAC time in the regulatory database?

commit 31559f35c5724976fd975e5d7e90cdb693b8dd27
Author: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Date:   Fri Feb 21 19:46:13 2014 +0100

    cfg80211: DFS get CAC time from regulatory database

    Send Channel Availability Check time as a parameter
    of start_radar_detection() callback.
    Get CAC time from regulatory database.

    Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

--
Kalle Valo