From owner-freebsd-hackers@FreeBSD.ORG Tue Aug 23 15:59:32 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 863C416A41F for ; Tue, 23 Aug 2005 15:59:32 +0000 (GMT) (envelope-from samuel.pierson@gmail.com) Received: from wproxy.gmail.com (wproxy.gmail.com [64.233.184.198]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1B6A743D46 for ; Tue, 23 Aug 2005 15:59:32 +0000 (GMT) (envelope-from samuel.pierson@gmail.com) Received: by wproxy.gmail.com with SMTP id i22so208354wra for ; Tue, 23 Aug 2005 08:59:31 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=A+div7kkBLFMA+vUvZAGkeZyozsAAijhlTOlQmzOIXD3ZJ6gURkiyG9mFmzI3L+kjsem5ODhtAi3c6EENVtaIHcZ50PdXnYdL2VGqrJdrr4YtctpREM+OGQ2TcpWGYgl3xD2HuLd/rxgO3F9Kec+3qdGnOXb2NMC9wLhAOuAIkE= Received: by 10.54.36.15 with SMTP id j15mr2322174wrj; Tue, 23 Aug 2005 08:59:31 -0700 (PDT) Received: by 10.54.144.1 with HTTP; Tue, 23 Aug 2005 08:59:31 -0700 (PDT) Message-ID: Date: Tue, 23 Aug 2005 10:59:31 -0500 From: Sam Pierson To: Sam Leffler , FreeBSD Hackers In-Reply-To: <42FACAF6.4020805@errno.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <42FACAF6.4020805@errno.com> Cc: Subject: Re: Global txpower in ath X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Aug 2005 15:59:32 -0000 On 8/10/05, Sam Leffler wrote: > Sam Pierson wrote: > > I noticed that when I control the signal strength through > > ifconfig, I can effectively reduce the signal when I set it > > as something like: ifconfig ath0 txpower 1. I have read > > that this input is device driver dependent and I couldn't > > find anything in the interface that handles txcontrol. Are > > these values taken in exactly or are they rounded to some > > less fine-grained control number? Thanks, >=20 > The current support has a limited number of settings for the tx power. > I don't recall how many there are but it's chip dependent and possibly > also frequency-specific. 5212 parts are capable of controlling txpower > on a per-packet basis but getting it "right" has proven very hard and is > not yet supported. >=20 > Sam >=20 I read that the Atheros chipset supports up to 60 different txpower options and like you said, it seems to be limited, to about 45 different settings at this point (ie: only txpower 1-45 are respected). The thing that has been bothering me is that the card is supposed to be capable of transmitting at like -90dBm (practically nothing, only good for=20 communication at a few meters with normal wireless cards) and at its lowest power setting, transmits like a -50 or -60 dBm signal. This ends up going like 60m before any significant signal loss. Are there _any_ cards at this point which support a global variable rate txpower and can transmit a signal only good for a few meters? Or is the support for these cards just not at that point yet? Even the cisco cards that I tried, which can supposedly transmit at 101 different levels, send like a -60dBm signal at its weakest strength. -Sam