From owner-freebsd-mobile@FreeBSD.ORG Thu May 27 08:24:00 2010 Return-Path: Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CB582106564A for ; Thu, 27 May 2010 08:24:00 +0000 (UTC) (envelope-from rpaulo@freebsd.org) Received: from karen.lavabit.com (karen.lavabit.com [72.249.41.33]) by mx1.freebsd.org (Postfix) with ESMTP id EF9D48FC22 for ; Thu, 27 May 2010 08:23:59 +0000 (UTC) Received: from e.earth.lavabit.com (e.earth.lavabit.com [192.168.111.14]) by karen.lavabit.com (Postfix) with ESMTP id 60D7615755F; Thu, 27 May 2010 03:23:58 -0500 (CDT) Received: from 10.0.10.3 (54.81.54.77.rev.vodafone.pt [77.54.81.54]) by lavabit.com with ESMTP id W2ES9TH6EG2R; Thu, 27 May 2010 03:23:58 -0500 Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: text/plain; charset=us-ascii From: Rui Paulo In-Reply-To: <4BFE260D.1090701@chlastak.cz> Date: Thu, 27 May 2010 09:23:54 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <4BFD9FE4.3090309@chlastak.cz> <4BFE260D.1090701@chlastak.cz> To: Miroslav Chlastak X-Mailer: Apple Mail (2.1078) Cc: freebsd-mobile@freebsd.org Subject: Re: Atheros and how to convert RSSI to dBm X-BeenThere: freebsd-mobile@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Mobile computing with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 May 2010 08:24:00 -0000 On 27 May 2010, at 08:58, Miroslav Chlastak wrote: > On 27.5.2010 02:16, Rui Paulo wrote: >> On 26 May 2010, at 23:25, Miroslav Chlastak wrote: >>=20 >> =20 >>> Hello, >>>=20 >>> is there a way how to convert RSSI from output of "ifconfig ath0 = list sta" to dBm?: >>>=20 >>> [snip] >>>=20 >>> ADDR AID CHAN RATE RSSI IDLE TXSEQ RXSEQ CAPS FLAG >>> 00:4f:62:1d:d8:5d 14 9 11M 18.5 0 15932 22400 ES A >>>=20 >>> [snip] >>>=20 >>> I my test enviroment I use this function: >>> noise floor + RSSI*2 =3D signal of client in dBm >>>=20 >>> Then i get the same value as from "tcpdump -n -i ath0 -p -y = IEEE802_11_RADIO": >>>=20 >>> [snip] >>>=20 >>> 10:41:04.746395 86402611933us tsft short preamble 58.5 Mb/s -61dB = signal -98dB noise antenna 1 [0x00000012] IP 10.0.0.1.2049> = 192.168.100.2.123: NTPv3, Client, length 48 >>>=20 >>> [snip] >>>=20 >>>=20 >>> Right? Or is this conversion "stupid"? Some better idea? >>>=20 >>> Is there a way how to get noise floor via "ifconfig"? I get it from = output of "athstats" :( >>> =20 >> No, there's no way right now. >>=20 >> Check this: = http://lists.freebsd.org/pipermail/freebsd-stable/2006-September/028895.ht= ml >>=20 >> Regards, >> -- >> Rui Paulo >>=20 >>=20 >> =20 >=20 > But this mail was sent on September 2006 - it's still impossible? :( >=20 > And how to do it tcpdump? >=20 > tcpdump -n -i ath0 -p -y IEEE802_11_RADIO": >=20 > [snip] >=20 > 10:41:04.746395 86402611933us tsft short preamble 58.5 Mb/s -61dB = signal -98dB noise antenna 1 [0x00000012] IP 10.0.0.1.2049> = 192.168.100.2.123: NTPv3, Client, length 48 >=20 > [snip] >=20 >=20 > Signal -61dB is right signal of my connected wireless client. Tcpdump = this signal "know", but system (via ifconfig) doesn't? Yes, that's right. The changes were not done yet to support displaying = this data in ifconfig. It's not hard to change ifconfig, what's hard is = changing every driver to provide useful info. ath passes this = information to radiotap the same way it provides this information to = athstats. Regards, -- Rui Paulo