From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x232.google.com (mail-qt0-x232.google.com [IPv6:2607:f8b0:400d:c0d::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D77903B29E for ; Sat, 4 Nov 2017 17:56:21 -0400 (EDT) Received: by mail-qt0-x232.google.com with SMTP id 1so7068254qtn.3 for ; Sat, 04 Nov 2017 14:56:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=GdcrJBHjqGNwuX2DxOdrrs5qSBTBOc+W2nINp3k0EWI=; b=XPUzuulmMYJdcX1keEVHFztcEfIgHriJwcpT4W9iKvsESjpRGhLoIPYXzBzgJdV7K+ Nz/FYTxJDXlqLOspxL1RtOGamlSueX5WvUoNJpnUTBGxO2s5N4WOOVD9NTIl1M/1e57K hqOjYmkVhPAqMtgrMF/fTXl1rDYwGaGnqOB2z2Y1OKGuWoxmzZOTTbuGyqFqCmZWfLju YuBf2ZW4QImHYNgIh91XO84R+bNCpeRw27amj4YPyQ2Mjut/60GjCp7EFf+ZoUUPWlwM kfh71DXF+d1gsOqbxe1I7fse5eLJUSwfLyhHOHvP33aLfmlBUz0T2nQ2TM6/82dpLZ8g BcWQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=GdcrJBHjqGNwuX2DxOdrrs5qSBTBOc+W2nINp3k0EWI=; b=QeaNfmnl896zrOuEApgOpZaetnDGRVlcn8uteJJcNQzLMqLWG+Q1fBva4InVNYceXE l82y7NvNWB/03akXo08p/UxS2Gl6TroGKGQztHbjVs6XJIelokHrg9oClccUAbUuEm/N 2+dnUyswIx4lH+Ii/jEas4e+dF2ImCc5X56e4vQ+GYty1KBS9jS0bLbzPGdzGiUo6pG2 /eAveEq7iF7ddZnQ7+cT9a8JXwN8mUF5p6mtB2RRMRkqXODyWwx4d4qHTE81DtGvhrSd 77mwPzgeA/+YarmayFWo3fKEa1nOkJZBfETYZ3qPqrPoqhu54zT1V4uxehowYQVc48C/ SrUg== X-Gm-Message-State: AMCzsaUa2wjnhyf4hp7YEdvyq+nhwjqDNOrMSc1fN+4grUpobvOvjiNr rdL+l6MB4iLv9SnME816AJj5YOuT0NZ6zdoeCAbPHw== X-Google-Smtp-Source: ABhQp+TmL+FC5Q3ZqtDPRbFvR6n4AFf9nCrOjITVywNSNF0WqzV0hDBgwwlx1GrQlR4i0QP1vjunFZworLMAZxyVIlc= X-Received: by 10.200.7.74 with SMTP id k10mr15573370qth.279.1509832581272; Sat, 04 Nov 2017 14:56:21 -0700 (PDT) MIME-Version: 1.0 Received: by 10.12.170.149 with HTTP; Sat, 4 Nov 2017 14:56:20 -0700 (PDT) In-Reply-To: <87h8u9n2db.fsf@toke.dk> References: <87tvybm0x2.fsf@toke.dk> <87h8u9n2db.fsf@toke.dk> From: Aaron Wood Date: Sat, 4 Nov 2017 14:56:20 -0700 Message-ID: To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: make-wifi-fast@lists.bufferbloat.net Content-Type: multipart/alternative; boundary="f403043a82ccad58cd055d2f4a44" 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 21:56:21 -0000 --f403043a82ccad58cd055d2f4a44 Content-Type: text/plain; charset="UTF-8" > 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... > Yeah, that's going to depend on the noise-floor of the receivers. I've found that -105dBm receive radios (other technologies) needed physical separation and cables rated at 60dB of shielding in order to keep cross-talk down. The cables from the SMA connectors to the boards are likely pretty leaky (the board connectors are probably u.fl connectors) --f403043a82ccad58cd055d2f4a44 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

=
As for cross-talk between antennas, I'm not sure this setup removes it<= br> 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...<= br>

Yeah, that's going to depend on the= noise-floor of the receivers.=C2=A0 I've found that -105dBm receive ra= dios (other technologies) needed physical separation and cables rated at 60= dB of shielding in order to keep cross-talk down.

= The cables from the SMA connectors to the boards are likely pretty leaky (t= he board connectors are probably u.fl connectors)=C2=A0
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