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 A4E103B29E for ; Sat, 4 Nov 2017 18:08:13 -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=1509833292; bh=lTdmkgRxRUx1dqxsNAUVZAVDB6J+fAAGZvYvXknWzAI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=iW01DXcm+mfc1pExi8D3ot/nbtS8dAl4Oxcyzz22LPHF/pQ57Py069/YHnhCz6z5t ScTee9PY0ImFf8Mwa4Wyb5tatB2hP9KgTjlc1EqVa6z7Aw9OlxncJ7h+PaOwc+bBuC hIVZpx8wLJXzdzKAWueMFQB4POvwGgsCR6YAO21mQ9sYobfmOouk4O4YnwXQZ6CRFL Uj8IdFEhgCqgn5PVFxKdlcpKI4bnO3AyEOW1m5WUJ8MzOmYpWzCbQ3HlNk1APzL42e vOn/4VTZjiKHyIZG9kCAMwrkGlt4a+xOKQJBXUlFG+XKEv+Uw9FNbidJ684r+ZTQkb //DORZrJGc3NQ== To: Aaron Wood Cc: make-wifi-fast@lists.bufferbloat.net In-Reply-To: References: <87tvybm0x2.fsf@toke.dk> <87h8u9n2db.fsf@toke.dk> Date: Sat, 04 Nov 2017 23:08:11 +0100 X-Clacks-Overhead: GNU Terry Pratchett Message-ID: <874lq9n1dg.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 22:08:13 -0000 Aaron Wood writes: >> 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. Yeah, I've heard similar reports from others. And I'm not really in a position to set that up; nor do I really need that much isolation between the nodes (I think). > The cables from the SMA connectors to the boards are likely pretty > leaky (the board connectors are probably u.fl connectors) Ah, yes, u.fl is what those are called. Indeed they are. So yeah, those cables don't exactly look like they have a lot of shielding on them... :) -Toke