From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.candelatech.com ([208.74.158.172]:50969 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755203Ab2JDWmB (ORCPT ); Thu, 4 Oct 2012 18:42:01 -0400 Message-ID: <506E10B7.4060406@candelatech.com> (sfid-20121005_004208_332055_06ABED6F) Date: Thu, 04 Oct 2012 15:41:59 -0700 From: Ben Greear MIME-Version: 1.0 To: Julian Calaby CC: "linux-wireless@vger.kernel.org" Subject: Re: Questions on direct-cabling 3x3 MIMO systems (ath9k) References: <506DDA1D.1090106@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 10/04/2012 03:36 PM, Julian Calaby wrote: > Hi Ben, > > On Fri, Oct 5, 2012 at 4:49 AM, Ben Greear wrote: >> I finally got my 3-attenuator system up and running, >> and I'm starting to do some tests. >> >> AP and Station are running 3.5.5+, ath9k ar9380 NICs. >> Channel 157, HT40, no encryption. >> >> One question right away: Should I expect decent performance >> if I directly cable 2 wifi NICs, where one is acting as AP and >> the other as station? I'm cabling ch0 to ch0, ch1 to ch1, ch2 to ch2. > > Going off on a tangent: arguably it shouldn't matter which channel on > the AP card is connected to which channel on the STA card. I wonder > what results you'd get if you cabled them in each combination and > tested the throughput keeping the other variables the same. I also > wonder what impact it would have on the throughput if you started > disconnecting the cables. I doubt it matters either....just seemed sane to start with something I could easily keep track of in my head :) I had really shitty performance when I had only one cable connected to the station, but I think it is probably related to rate-control, which seems too aggressive. When I force things to slower speeds it works fine. I'm starting to look into that now. I hope to eventually produce big pretty graphs reporting signal, rx-rate, etc over various attenuations...but still got a ways to go first! Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com