From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.thunk.org (imap.thunk.org [IPv6:2600:3c02::f03c:91ff:fe96:be03]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "imap.thunk.org", Issuer "CAcert Class 3 Root" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id C946321F1BB for ; Tue, 17 Dec 2013 17:33:10 -0800 (PST) Received: from root (helo=closure.thunk.org) by imap.thunk.org with local-esmtp (Exim 4.80) (envelope-from ) id 1Vt60Y-0003RQ-1V; Wed, 18 Dec 2013 01:33:06 +0000 Received: by closure.thunk.org (Postfix, from userid 15806) id 8CF1E58102F; Tue, 17 Dec 2013 20:33:03 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=thunk.org; s=mail; t=1387330383; bh=yIdNQo+c4U+aUDuztsVHUPCNlvF+Juicq9W/mX4QcXw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HVsUPVMaOhF8dksJTKKWsdSk7PPdcdBx6aAry+9jlSI5XfZvz7wSoc9P7Dk4yUr2m EXVJW/tVF80zz3m7DKATZ6Jvrc5dXv9HdfAwkzjinYD94soulCJwgDeH6HroNVoOZy SrhYLxPcILPARgi8EgzvBKpbjJT2VfNIOyDFo/5A= Date: Tue, 17 Dec 2013 20:33:03 -0500 From: Theodore Ts'o To: Stephen Hemminger Message-ID: <20131218013303.GA19261@thunk.org> References: <52AF797E.6030600@imap.cc> <18972.1387302855@sandelman.ca> <1387319157.48330794@apps.rackspace.com> <20131217154345.0e91b65f@nehalam.linuxnetplumber.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131217154345.0e91b65f@nehalam.linuxnetplumber.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Cc: "cerowrt-devel@lists.bufferbloat.net" Subject: Re: [Cerowrt-devel] treating 2.4ghz as -legacy? X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Dec 2013 01:33:11 -0000 On Tue, Dec 17, 2013 at 03:43:45PM -0800, Stephen Hemminger wrote: > I concur with Jim. > > My observation is that in our house, upstairs the 5Ghz AP has low > signal strength reported by the devices, and poor bandwidth. > > Could it be that the radiation pattern of the antenna in WDR3800 > laying horizontally is different for each band. Maybe the 5Ghz band > is more of a squashed donut? I haven't done a careful study with the WNDR3800 running CeroWRT, but with my previous dual-band AP's, where my AP is located in the attic of my house, 5GHz works great on the 2nd floor, but on the first floor, it's very spotty; it tends to depend on the quality of the antenna (or WiFI chipset; that's not entirely clear) of the laptop or mobile handset involved. Some models show low signal strength on the 5GHz band; other models simply don't work at all on 5GHz. So it may be an "urban legend" that 5GHz penetrates residential housing materials more poorly than 2.4GHz radio waves, but all I can tell you is that 5GHz is definitely much works much more poorly in my house. I don't know if it has to do with the antenna quality, or the radio quality, at either the AP or the client, but it's definitely an observable phenomena. I'll have to program in the 5GHz SSID into some of my devices that historically have completely failed to function on 5GHz when on the first floor of my house (but which work just fine on the 2nd floor) to see if things are any better with CeroWRT running on the WNDR3800. I don't mind using multiple routers, if at some point CeroWRT were to gain the advanced feature of talking to other routers and forcing a disassociation when the signal strength talking to a particular client gets significantly weaker than compared to the signal strength from another AP. Is there any special hardware support needed to do this kind of AP-to-AP handoff, or is it just really complicated and no one has bothered to do it in an open source implementation? Cheers, - Ted