From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp65.iad3a.emailsrvr.com (smtp65.iad3a.emailsrvr.com [173.203.187.65]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 4A5193B2C2 for ; Fri, 24 Jun 2016 17:24:25 -0400 (EDT) Received: from smtp25.relay.iad3a.emailsrvr.com (localhost.localdomain [127.0.0.1]) by smtp25.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id 0FBF0180426; Fri, 24 Jun 2016 17:24:25 -0400 (EDT) Received: from app20.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by smtp25.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id 00CE7180203; Fri, 24 Jun 2016 17:24:24 -0400 (EDT) X-Sender-Id: MAILER-DAEMON Received: from app20.wa-webapps.iad3a (relay-webapps.rsapps.net [172.27.255.140]) by 0.0.0.0:25 (trex/5.5.4); Fri, 24 Jun 2016 17:24:25 -0400 Received: from reed.com (localhost [127.0.0.1]) by app20.wa-webapps.iad3a (Postfix) with ESMTP id E303EE1801; Fri, 24 Jun 2016 17:24:24 -0400 (EDT) Received: by mobile.rackspace.com (Authenticated sender: dpreed@reed.com, from: dpreed@reed.com) with HTTP; Fri, 24 Jun 2016 17:24:24 -0400 (EDT) Date: Fri, 24 Jun 2016 17:24:24 -0400 (EDT) From: dpreed@reed.com To: "David Lang" Cc: "Bob McMahon" , make-wifi-fast@lists.bufferbloat.net, "cerowrt-devel@lists.bufferbloat.net" MIME-Version: 1.0 Content-Type: text/plain;charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Message-ID: <1466803464.927322699@mobile.rackspace.com> X-Mailer: mobile/4.0.0 Subject: Re: [Cerowrt-devel] [Make-wifi-fast] more well funded attempts showing market demandfor better wifi X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 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: Fri, 24 Jun 2016 21:24:25 -0000 Without custom silicon, doing what I was talking about would involve non st= andard MAC power management, which would require all devices to agree. David Lang's explanation was the essence of what I meant. the transmission = from access point on multiple channels is just digital addition if the DACs= have enough bits per sample. to make sure that the signals to the AP are e= qualized, just transmit at a power that makes that approximately true... wh= ich means a power amp with at most 30 dB of dynamic gain setting. typical d= ynamic path attenuation range (strongest to weakest ratio) among stations s= erved by an AP is < 20 dB from my past experiments on well operating-instal= ltions, but 25 can be seen in reflection heavy environments.-----Original M= essage----- From: "David Lang" Sent: Fri, Jun 24, 2016 at 1:19 am To: "Bob McMahon" Cc: "Bob McMahon" , make-wifi-fast@lists.bufferbl= oat.net, "cerowrt-devel@lists.bufferbloat.net" Subject: Re: [Make-wifi-fast] more well funded attempts showing market dema= ndfor better wifi well, with the kickstarter, I think they are selling a bill of goods. Just using the DFS channels and aggregating them as supported by N and AC= =20 standards would do wonders (as long as others near you don't do the same) David Lang On Thu, 23 Jun 2016, Bob McMahon wrote: > Date: Thu, 23 Jun 2016 20:01:22 -0700 > From: Bob McMahon=20 > To: David Lang=20 > Cc: dpreed@reed.com, make-wifi-fast@lists.bufferbloat.net, > "cerowrt-devel@lists.bufferbloat.net" > =20 > Subject: Re: [Make-wifi-fast] more well funded attempts showing market de= mand > for better wifi >=20 > Thanks for the clarification. Though now I'm confused about how all the > channels would be used simultaneously with an AP only solution (which is = my > understanding of the kickstarter campaign.) > > Bob > > On Thu, Jun 23, 2016 at 7:14 PM, David Lang wrote: > >> I think he is meaning when one unit is talking to one AP the signal leve= ls >> across multiple channels will be similar. Which is probably fairly true. >> >> >> David Lang >> >> On Thu, 23 Jun 2016, Bob McMahon wrote: >> >> Curious, where does the "in a LAN setup, the variability in [receive] >>> signal strength is likely small enough" assertion come? Any specific >>> power numbers here? We test with many combinations of "signal strength >>> variability" (e.g. deltas range from 0 dBm - 50 dBm) and per different >>> channel conditions. This includes power variability within the spatial >>> streams' MiMO transmission. It would be helpful to have some physics >>> combined with engineering to produce some pragmatic limits to this. >>> >>> Also, mobile devices have a goal of reducing power in order to be >>> efficient >>> with their battery (vs a goal to balance power such that an AP can >>> receive simultaneously.) Power per bit usually trumps most other desig= n >>> goals. There market for battery powered wi-fi devices drives a >>> semi-conductor mfg's revenue so my information come with that bias. >>> >>> Bob >>> >>> On Thu, Jun 23, 2016 at 1:48 PM, wrote: >>> >>> The actual issues of transmitting on multiple channels at the same time >>>> are quite minor if you do the work in the digital domain (pre-DAC). Y= ou >>>> just need a higher sampling rate in the DAC and add the two signals >>>> together (and use a wideband filter that covers all the channels). No= RF >>>> problem. >>>> >>>> Receiving multiple transmissions in different channels is pretty much = the >>>> same problem - just digitize (ADC) a wider bandwidth and separate in t= he >>>> digital domain. the only real issue on receive is equalization - if y= ou >>>> receive two different signals at different receive signal strengths, t= he >>>> lower strength signal won't get as much dynamic range in its samples. >>>> >>>> But in a LAN setup, the variability in signal strength is likely small >>>> enough that you can cover that with more ADC bits (or have the MAC >>>> protocol >>>> manage the station transmit power so that signals received at the AP a= re >>>> nearly the same power. >>>> >>>> Equalization at transmit works very well when there is a central AP (a= s >>>> in >>>> cellular or normal WiFi systems). >>>> >>>> >>>> >>>> On Thursday, June 23, 2016 4:28pm, "Bob McMahon" >>> bob.mcmahon@broad= com.com> >>>> said: >>>> >>>> _______________________________________________ >>>>> Make-wifi-fast mailing list >>>>> Make-wifi-fast@lists.bufferbloat.net >>>>> https://lists.bufferbloat.net/listinfo/make-wifi-fast >>>>> An AP per room/area, reducing the tx power (beacon range) has been my >>>>> approach and has scaled very well. It does require some wires to ea= ch >>>>> >>>> AP >>>> >>>>> but I find that paying an electrician to run some quality wiring to >>>>> >>>> things >>>> >>>>> that are to remain stationary has been well worth the cost. >>>>> >>>>> just my $0.02, >>>>> Bob >>>>> >>>>> On Thu, Jun 23, 2016 at 1:10 PM, David Lang wrote: >>>>> >>>>> Well, just using the 5GHz DFS channels in 80MHz or 160 MHz wide chunk= s >>>>>> would be a huge improvement, not many people are using them (yet), a= nd >>>>>> >>>>> the >>>> >>>>> wide channels let you get a lot of data out at once. If everything is >>>>>> within a good range of the AP, this would work pretty well. If you e= nd >>>>>> >>>>> up >>>> >>>>> needing multiple APs, or you have many stations, I expect that you wi= ll >>>>>> >>>>> be >>>> >>>>> better off with more APs at lower power, each using different channel= s. >>>>>> >>>>>> David Lang >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Thu, 23 Jun 2016, Bob McMahon wrote: >>>>>> >>>>>> Date: Thu, 23 Jun 2016 12:55:19 -0700 >>>>>> >>>>>>> From: Bob McMahon=20 >>>>>>> To: Dave Taht=20 >>>>>>> Cc: make-wifi-fast@lists.bufferbloat.net, >>>>>>> "cerowrt-devel@lists.bufferbloat.net" >>>>>>> =20 >>>>>>> Subject: Re: [Make-wifi-fast] more well funded attempts showing mar= ket >>>>>>> demand >>>>>>> for better wifi >>>>>>> >>>>>>> >>>>>>> hmm, I'm skeptical. To use multiple carriers simultaneously is >>>>>>> >>>>>> difficult >>>> >>>>> per RF issues. Even if that is somehow resolved, to increase >>>>>>> >>>>>> throughput >>>> >>>>> usually requires some form of channel bonding, i.e. needed on both >>>>>>> >>>>>> sides, >>>> >>>>> and brings in issues with preserving frame ordering. If this is just >>>>>>> channel hopping, that needs coordination between both sides (and is= n't >>>>>>> simultaneous, possibly costing more than any potential gain.) An = AP >>>>>>> >>>>>> only >>>> >>>>> solution can use channel switch announcements (CSA) but there is a >>>>>>> >>>>>> cost to >>>> >>>>> those as well. >>>>>>> >>>>>>> I guess don't see any break though here and the marketing on the si= te >>>>>>> seems >>>>>>> to indicate something beyond physics, at least the physics that I >>>>>>> understand. Always willing to learn and be corrected if I'm >>>>>>> misunderstanding things. >>>>>>> >>>>>>> Bob >>>>>>> >>>>>>> On Wed, Jun 22, 2016 at 10:18 AM, Dave Taht=20 >>>>>>> >>>>>> wrote: >>>> >>>>> >>>>>>> On Wed, Jun 22, 2016 at 10:03 AM, Dave Taht=20 >>>>>>> >>>>>> wrote: >>>> >>>>> >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wi= fi?ref=3Dbackerkit >>>> >>>>> >>>>>>>> >>>>>>>>> "Portal is the first and only router specifically engineered to c= ut >>>>>>>>> through and avoid congestion, delivering consistent, >>>>>>>>> high-performance >>>>>>>>> WiFi with greater coverage throughout your home. >>>>>>>>> >>>>>>>>> Its proprietary spectrum turbocharger technology provides access = to >>>>>>>>> 300% more of the radio airwaves than any other router, improving >>>>>>>>> performance by as much as 300x, and range and coverage by as much= as >>>>>>>>> 2x in crowded settings, such as city homes and multi-unit >>>>>>>>> apartments" >>>>>>>>> >>>>>>>>> It sounds like they are promising working DFS support. >>>>>>>>> >>>>>>>>> >>>>>>>> It's not clear what chipset they are using (they are claiming wave= 2) >>>>>>>> - >>>>>>>> but they are at least publicly claiming to be using openwrt. So I >>>>>>>> threw in enough to order one for september, just so I could commen= t >>>>>>>> on >>>>>>>> their kickstarter page. :) >>>>>>>> >>>>>>>> I'd have loved to have got in earlier (early shipments are this mo= nth >>>>>>>> apparently), but those were sold out. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wi= fi/comments >>>> >>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>>> Dave T=C3=A4ht >>>>>>>>> Let's go make home routers and wifi faster! With better software! >>>>>>>>> http://blog.cerowrt.org >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>> Dave T=C3=A4ht >>>>>>>> Let's go make home routers and wifi faster! With better software! >>>>>>>> http://blog.cerowrt.org >>>>>>>> _______________________________________________ >>>>>>>> Make-wifi-fast mailing list >>>>>>>> Make-wifi-fast@lists.bufferbloat.net >>>>>>>> https://lists.bufferbloat.net/listinfo/make-wifi-fast >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>> Make-wifi-fast mailing list >>>>>> Make-wifi-fast@lists.bufferbloat.net >>>>>> https://lists.bufferbloat.net/listinfo/make-wifi-fast >>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>>> >