From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:36521 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756381Ab2HWVUi (ORCPT ); Thu, 23 Aug 2012 17:20:38 -0400 Message-ID: <50369EA4.7030609@candelatech.com> (sfid-20120823_232042_486700_242B7538) Date: Thu, 23 Aug 2012 14:20:36 -0700 From: Ben Greear MIME-Version: 1.0 To: Paul Stewart CC: "linux-wireless@vger.kernel.org" Subject: Re: Any suggestions for programmable attenuators? References: <50117096.8010706@candelatech.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 07/26/2012 10:29 AM, Paul Stewart wrote: > We have a few units from eubus (http://www.eubus.net, ATS0760-95). > They're fairly easy to interface to (we're controlling them with a > BeagleBone, but need level shifting because they are 5V devices). We > don't have a whole lot of seat time with them so far, but we've > validated that they work. I've managed to wire up some of these as well (using Arduino as controller). One thing I notice is that the smallest signal quality I can see reported by the NIC (ath9k) is about -81 or -82 dBm. Technically, the attenuator should be able to go below the noise floor of around -90dbm if I understand things properly. Have you done any testing of this nature? And for what it's worth, using ath9k, 1x1 MIMO (one channel) /n, ht40 on 5ghz, I get almost 8Mbps UDP download at -80 dBm signal quality :) Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com