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 8C1B33B29E for ; Sat, 4 Nov 2017 17:47:13 -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=1509832031; bh=0k2dSTV09aimYZ/6L2d+Fbt8zFU5HvnXCJZWrm4NySo=; h=From:To:Subject:In-Reply-To:References:Date:From; b=HIjjpoRVL7X5uX+qyOIAcKfZLiX/tQLRrMmLWUOJyvdL7jtQS0jbCamQWKgVjXTy0 x+pA+x3URO8HrI5nPc8PP7WRmKRtrt1VLnkPykvdQsIrmCQPus1Vl6GpBFiVUoGdgZ cKOAvutNNGW+JabwPEaMuKISTUNqgi/VTchIZ8spn2WHMBcbtjjiXoZNubQWLnDGsM kXOnSoH1Am0F7mo/H9S1hb7rCMSeSy9ajQx6a7Vu2960IaxGGIe2Tf06I+DzScO4ui KGpxg4igHxgfSkSgykQwubT4CXEZYImA1D42dP5chmwAdZCxn40MJnYg/cg69Yh0BY DsHvDXooPKLWA== To: Aaron Wood , make-wifi-fast@lists.bufferbloat.net In-Reply-To: References: <87tvybm0x2.fsf@toke.dk> Date: Sat, 04 Nov 2017 22:46:40 +0100 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <87h8u9n2db.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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 21:47:13 -0000 Aaron Wood writes: > What this setup also removes is random noise, which is good for > repeatability, but bad for real-life testing. My experiences doing similar > are that there isn=E2=80=99t much of a grey area between a =E2=80=9Cgreat= =E2=80=9D > throughput/packet error rate and =E2=80=9Cnothing works=E2=80=9D. > > It also removes the real-world crosstalk between the antennas. > > So good for some things, especially automated tests, but it=E2=80=99s not= a > replacement for real field tests in the presence of random noise. Yeah, I agree that real-world testing is needed on top of this. But for my own needs I consider repeatability more important than strict correspondence to a real-world scenario (whatever that means). But you're right, of course, that it would be bad if this is the only type of testing that is done :) As for cross-talk between antennas, I'm not sure this setup removes it completely; there's probably leakage around connectors, and possibly in the cables attaching the outwards-facing SMA connectors on each machine to whatever the tiny connectors on the cards are called. Don't have the equipment to measure any of that, though, so for now it remains a hunch... -Toke