From owner-freebsd-mobile Sun Aug 4 22:20:13 2002 Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9CC8037B400 for ; Sun, 4 Aug 2002 22:20:08 -0700 (PDT) Received: from harmony.village.org (rover.bsdimp.com [204.144.255.66]) by mx1.FreeBSD.org (Postfix) with ESMTP id D478943E4A for ; Sun, 4 Aug 2002 22:20:07 -0700 (PDT) (envelope-from imp@bsdimp.com) Received: from localhost (warner@rover2.village.org [10.0.0.1]) by harmony.village.org (8.12.5/8.12.3) with ESMTP id g755K69R063561; Sun, 4 Aug 2002 23:20:06 -0600 (MDT) (envelope-from imp@bsdimp.com) Date: Sun, 04 Aug 2002 23:19:36 -0600 (MDT) Message-Id: <20020804.231936.118756968.imp@bsdimp.com> To: geekvinod@yahoo.com Cc: freebsd-mobile@FreeBSD.ORG Subject: Re: Comms quality/signal noise stat From: "M. Warner Losh" In-Reply-To: <20020805035753.79107.qmail@web21107.mail.yahoo.com> References: <20020805035753.79107.qmail@web21107.mail.yahoo.com> X-Mailer: Mew version 2.1 on Emacs 21.2 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-mobile@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org In message: <20020805035753.79107.qmail@web21107.mail.yahoo.com> Vinod writes: : can anybody explain to me a little bit more about the : Comms quality/signal noise stat appearing with : wicontrol . it always seems to show [ 0 27 27 ].how : can this stat be used to monitor the current S/N : ratio,if it can at all. The numbers are random. It depends on the card, the firmware and a number of other things. If you have a lucent card, then you likely are going to be able to convert them to a dBm at the receiver by adding -149 to them. However, there are some times that this number is not valid. If you are dealing with lucent cards, there's a number of different ways to convert this number to dBm. Some versions you can add -100 to the number to get approximate dBm. Other versions you do -100 + (N * 255 / 100) other versions do other things. Newer firmware for the prism cards have a special dBm query you can do (from 1.3 and newer, although 1.0 seems to have some of this functionality). wicontrol -C automatically subtracts -149 from the numbers. So to convert them to dBm, you need need to add 149 before doing the above transform. Oh, and symbol have numbers that have yet another, different conversion factor. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message