From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.toke.dk (mail.toke.dk [52.28.52.200]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 1AE343B29E for ; Sat, 4 Nov 2017 17:48:43 -0400 (EDT) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1509832121; bh=w/gw9pimeK0VbirY6dvEcttn6k25wsiuihFeXPjKEgA=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=v821TkQlx/Vh5vaFy7Dblt3Qna6gqqnrYA8taU/NM0OC35Y8OYpgVdXVn2wdj5tWl +wlOWHs78y+sK/OjjPmU8WHqxflfFYAqwR4GAp8vW62W8+WZ7RmF8IMMQuP+M3YIlV fzgjQz+eeFHUOYelq9Ly0j4037tF9RRmb6coAogUU4CRKUWT8Rdv61yXIBxb6VANxK 5S/iz31Ve+487rwfKEXP8FOyohA2i1OZsYVs/XcVrhlYBLfKH3wV+WjZ+Aw8yV6ZhB jWwgWL/j/zLDPLVdTj0e0RH+BT0eGYoogha27/C9gJ9er/KCeXV5zyYQdS0mYqfZUu fZrA11xf9Wi0A== To: Bob McMahon , Aaron Wood Cc: make-wifi-fast@lists.bufferbloat.net In-Reply-To: References: <87tvybm0x2.fsf@toke.dk> Date: Sat, 04 Nov 2017 22:48:10 +0100 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <87efpdn2at.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Make-wifi-fast] Wiring up a wireless testbed X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Nov 2017 21:48:43 -0000 Bob McMahon writes: > A way I think about is to emulate the "system" in both range/power > (attenuation) and in mixing (phase shifts) It's a diagonal matrix for > range feeding into an h-matrix for the mixing. A butler matrix can be used > for the latter if variable phase control isn't required, e.g. you don't > care about spatial stream relative powers. > > On adding energy for "random" noise, some knobs of concern are the energy > detect on the tx and signal floor for the rx. These sources can be fed > into the same h-matrix through their own d-matrices. This won't replace > field tests but helps get closer towards that while providing for repeat > ability. What equipment would it take to do something like that? > Also, equally important by my judgment, though not related to wireless, is > to synchronize the clocks on the PCs. An oven controlled oscillator and > PTP works well towards that goal. Yeah, already using PTP in my testbed; quite essential for measuring one-way delay. -Toke