From owner-freebsd-mobile@FreeBSD.ORG Wed May 26 22:43:51 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 411F01065670 for ; Wed, 26 May 2010 22:43:51 +0000 (UTC) (envelope-from mira@chlastak.cz) Received: from mail.intime.cz (mail.intime.cz [88.208.96.252]) by mx1.freebsd.org (Postfix) with ESMTP id F25308FC1F for ; Wed, 26 May 2010 22:43:50 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mail.intime.cz (Postfix) with ESMTP id 1861982EDF0 for ; Thu, 27 May 2010 00:25:47 +0200 (CEST) X-Virus-Scanned: amavisd-new at mail.intime.cz Received: from mail.intime.cz ([127.0.0.1]) by localhost (mail.intime.cz [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NKSGXzHegOgG for ; Thu, 27 May 2010 00:25:46 +0200 (CEST) Received: from [192.168.200.100] (192.13.broadband2.iol.cz [83.208.13.192]) by mail.intime.cz (Postfix) with ESMTPSA id 2542C82EDE6 for ; Thu, 27 May 2010 00:25:46 +0200 (CEST) Message-ID: <4BFD9FE4.3090309@chlastak.cz> Date: Thu, 27 May 2010 00:25:40 +0200 From: Miroslav Chlastak User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9pre) Gecko/20100308 Lightning/1.0b1 Shredder/3.0.4pre MIME-Version: 1.0 To: freebsd-mobile@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Wed, 26 May 2010 22:53:31 +0000 Subject: 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: Wed, 26 May 2010 22:43:51 -0000 Hello, is there a way how to convert RSSI from output of "ifconfig ath0 list sta" to dBm?: [snip] 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 [snip] I my test enviroment I use this function: noise floor + RSSI*2 = signal of client in dBm Then i get the same value as from "tcpdump -n -i ath0 -p -y IEEE802_11_RADIO": [snip] 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 [snip] Right? Or is this conversion "stupid"? Some better idea? Is there a way how to get noise floor via "ifconfig"? I get it from output of "athstats" :( -- Mira