From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; dkim=pass header.d=lang.hm header.i=@lang.hm header.a=rsa-sha256 header.s=mail2026 header.b=p0pq91ti; arc=none (Message is not ARC signed); dmarc=pass (Used From Domain Record) header.from=lang.hm policy.dmarc=none Received: from mail.lang.hm (mail.lang.hm [70.167.213.146]) by mail.toke.dk (Postfix) with ESMTPS id 112CB16CC93D for ; Tue, 22 Sep 2026 07:05:41 +0200 (CEST) Received: from [10.2.3.133] (unknown [10.2.3.133]) by mail.lang.hm (Postfix) with ESMTP id 35A32238118; Mon, 21 Sep 2026 22:05:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lang.hm; s=mail2026; t=1790053538; bh=9hNaEHDAEleSJZdYHNnVdQ/3jtVGpeYxJSM2hKw/cBo=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=p0pq91tiaWzHfe16c+pFqweJrP4aLI7CKDk44076+vB5QmU5g8p0bTXFm/sTNh6Jn Ux4QLRhPLz2gn57vwU1MHpZlDhuGYXfHKikU4/Y7z5IPBImiHBLCd6b5CW5uSewTik veqWQDZMhwPzVJml11EOpSD2glEildHQR4EOqVA6dKUtNn17X3jVtZuBoDNZ93f6Uj bSm030FnVGRC/2N4rAqRlqGn/kFAnBJYO+QGjMxeb1oue/V3FSn9+52lKEkZTh7Hyf Lw+Iv8VaZPcftToDs7BjV1MsJeWl293MA8+6fmrKqREgKif3hHXV30MExBQS5Q6DNy Z08zGlJpvvkBA== Date: Mon, 21 Sep 2026 22:05:33 -0700 (MST) From: David Lang To: Michael Richardson cc: David Lang , bloat@lists.bufferbloat.net In-Reply-To: <30953.1790007837@obiwan.sandelman.ca> Message-ID: <25379pq5-8rn0-2qq7-60n5-5p51451n0537@ynat.uz> References: <178979811506.1938.15903254559639098502@gauss> <1onq9q61-40o3-pnn6-pns7-58np93687005@ynat.uz> <817d1dce471ea24bcd552ffd5f38e240@umbernetworks.com> <72po68s0-qo56-2304-51s1-830r5qo1n6s2@ynat.uz> <30953.1790007837@obiwan.sandelman.ca> MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset=US-ASCII Message-ID-Hash: B4HU7Z7WYPJD3BC7LVJNE3AVPLIAHSVG X-Message-ID-Hash: B4HU7Z7WYPJD3BC7LVJNE3AVPLIAHSVG X-MailFrom: david@lang.hm X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list Subject: [Bloat] Re: Vol 185, Issue 5 List-Id: General list for discussing Bufferbloat Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Michael Richardson wrote: > David Lang wrote: > > It interprets loss as "this is a weak signal, let me do things that will help > > in the weak signal case", slowing the transmission speed, which helps in the > > face of general noise, but when the problem is interference from other wifi > > transmitters, it instead expands the window where the interference will > > clobber the retransmission. > > That's a very nice, consise explanation. Thank you. We need a word for this > https://en.wikipedia.org/wiki/Scaredy_Squirrel_(TV_series) like behaviour :-) > > > This is why at the Scale conference, we use a LOT of APs, all turned down to > > very low power and with default or worse antennas on them to shrink the > > transmission range of the APs. > > I wonder if this is written down somewhere? I tried to cover it in this llogin article https://www.usenix.org/publications/login/april-2013-volume-38-number-2/wireless-means-radio and LISA talk https://www.usenix.org/conference/lisa12/technical-sessions/presentation/lang_david_wireless > I think that the IETF NOC tried to write this up at some point, but I'm not > sure if it went anywhere. > > I was told that the enterprise-scale systems (where half of the AP function > reside in a switch) will use an AP high in the air when the room has few > people/stations, but then switch to APs on chairs as the room fills. > The mobile bags of water in the chairs are part of the sheilding :-) I haven't seen an Enterprise system do that, but that is what I do, (using that terminology) so word may be filtering out Enterprise APs tend to be expensive and so people don't install that many of them. they also tend to put multiple sets of radios in a single ap. Which is great is you want to use all the channels in once place, but a problem if you want to re-use any of those channels. Even the ones with directional antennas (tend to be 4 sets of antennas) have a problem. in theory they can re-use channels this way in different directions, in practice the stations they are talking to hear the other mobile stations that are in another quadrent. again, all things that work really well when the building is empty and they are installing and testing the system, but don't work that well when a lot of people are there using it (let alone when you try to do a classroom) David Lang > -- > ] Never tell me the odds! | ipv6 mesh networks [ > ] Michael Richardson, Sandelman Software Works | IoT architect [ > ] mcr@sandelman.ca http://www.sandelman.ca/ | ruby on rails [ > ] My working hours and your working hours may be different. [ > ] Please do not feel obligated to reply outside your normal working hours [ > > >