From owner-freebsd-wireless@FreeBSD.ORG Wed Aug 22 05:39:08 2012 Return-Path: Delivered-To: freebsd-wireless@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id C90E0106566B for ; Wed, 22 Aug 2012 05:39:08 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-ob0-f182.google.com (mail-ob0-f182.google.com [209.85.214.182]) by mx1.freebsd.org (Postfix) with ESMTP id 82FA98FC0A for ; Wed, 22 Aug 2012 05:39:08 +0000 (UTC) Received: by obbun3 with SMTP id un3so1122067obb.13 for ; Tue, 21 Aug 2012 22:39:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=DJN1+mmLbNzS6Y8vAqVX02us5/MXPR/xIFLLxdADWuI=; b=UyN9cbr9ASpBmbxy1CFYUCcByWeVGYzHlEhJdjvQ7Xeq8riA9qKUg9+Se9JFtFBCsz FGvqcCvRjqnr9OchQCAqXqXOGv/FEt5JOXWpiNhA5h1EG4uukX/O/vzWAi2pbyXRcPGn P0+UsqkepjhCcYX7J94TWYw5ZR1fYOKYHDqjE6Wwp2rx3b0CzLWPaTTiRSMelfVJs8Kk uwT0TPyfoLeCNwoNgkRvuoDDliwmrrSHD6ZaE/ow2eRlW2ngBfKvikf5MmX3xsDvnHEg HlwygfLY9+TUcZyUsnxiGh/qCPXN4A3IIwpoN5nR9n0djtvi2uDzApNtGxGhEtmgATCg uTkQ== MIME-Version: 1.0 Received: by 10.60.10.194 with SMTP id k2mr14628382oeb.127.1345613947688; Tue, 21 Aug 2012 22:39:07 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.76.8.98 with HTTP; Tue, 21 Aug 2012 22:39:07 -0700 (PDT) Received: by 10.76.8.98 with HTTP; Tue, 21 Aug 2012 22:39:07 -0700 (PDT) In-Reply-To: <475A4E02EFF4724A9E58F55A56AC13160661E6AC@APEVS1.ap.ci.root> References: <475A4E02EFF4724A9E58F55A56AC13160641D618@APEVS1.ap.ci.root> <475A4E02EFF4724A9E58F55A56AC13160661E6AC@APEVS1.ap.ci.root> Date: Tue, 21 Aug 2012 22:39:07 -0700 X-Google-Sender-Auth: 2hCh7YC3nL-F3arqxV2eQLQqt0s Message-ID: From: Adrian Chadd To: "Wright, Brett" Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-wireless@freebsd.org, Kim Culhan Subject: RE: Atheros DFS radar detection X-BeenThere: freebsd-wireless@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Discussions of 802.11 stack, tools device driver development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Aug 2012 05:39:08 -0000 Oh. Disable ANI too. Adrian On Aug 21, 2012 10:15 PM, "Wright, Brett" wrote: > > -----Original Message----- > > From: adrian.chadd@gmail.com [mailto:adrian.chadd@gmail.com] On Behalf > > Of Adrian Chadd > > > > Brett, did you have any luck? > > > > I'll be in a position to test out with some AR5212 era NICs this week. > > > > Adrian > > > > Hi Adrian, > > I have been mucking around with the radar parameters for several days > now. In order to get reasonably low levels of false detects I need very > aggressive (at least I *think* they are aggressive) values for the radar > parameters. For example: > > FIRPWR: -33 > RRSSI: 45 > HEIGHT: 28 > PRSSI: 22 > INBAND: 6 > > However, the meaning of these parameters is still a little unclear to > me. I have read the patent document many times but there is still a lot > of information I do not know. I would be prepared to bet that Atheros > has documentation describing the above parameters with a lot more > clarity. For example , just to pick one of the parameters FIRPWR: > According to the comment for this field it is a threshold that the > signal power must exceed, but it's default value is -41dBm. Now -41dBm > is VERY strong! Also, my experimentally derived value of -31dBm is way > stronger still. Certainly in my test environment the strongest signals > are around -55dBm (way weaker than either of these values). This really > highlights to me that I am "missing" something... > > Also, the parameter I found makes the biggest difference to my false > detects is RRSSI which is "the threshold that the RSSI must exceed when > AGC is OK..." etc. Is this a SNR? If so 45dB (my setting for this > parameter) with a noise floor around -95dBm would equate to an absolute > RSSI of -50dBm. Am I reading this correctly? And if it is an SNR, then > why is FIRPWR apparently an actual RSSI (i.e. absolute level). Is > everything other than FIRPWR an SNR? > > Finally, I haven't yet taken the next step of actually injecting radar > pulses, but my suspicion is that with such aggressive parameters that > actual radar detection according to the regulatory test patterns will > fail. > > I do realize that the difficulties I'm having are due to my lack of > information and understanding, however any light you may be able to shed > would be greatly appreciated. > > Thanks > Brett > >