From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x234.google.com (mail-wm0-x234.google.com [IPv6:2a00:1450:400c:c09::234]) (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 2C1903B2E2 for ; Thu, 23 Jun 2016 23:01:24 -0400 (EDT) Received: by mail-wm0-x234.google.com with SMTP id a66so7388032wme.0 for ; Thu, 23 Jun 2016 20:01:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=5puDYMwuMqq0WFveAR/+asCvGaOhp/55UEjkrhOyhxw=; b=GTXSvzG1AMEv6w0RF5r58acPEb+imfSZ74hOOFUNhfFkRxQlAZV9pZ84bRC4OIxqck E63BmG4n1H+OPoz2hl3DEguj/AJ4YqZEwD2nqdo3r9K0kwNBQg/rsTiEtaKuJrvSfEy7 /hGW58bPEuYqqjeFa6NjKiw5i88OUeTUfP1Qs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=5puDYMwuMqq0WFveAR/+asCvGaOhp/55UEjkrhOyhxw=; b=UP1oENROpVsRlXVrt91FWcNFo2n5vgUwTAqVeubbSDLd2NmVvD8iJq7yhHpWMYfo5U CjFMnODrbePVqt+VFo3whUd4vVpvSYQLBUhh1fjZEBO5ZHnL6He2eKdk05bYtsdsj86D MUffncqYn52BCuLCaY+t9StDLHJk2fFvW2zRr9ObkSpyIvXuvTL59WsOds03rLLU4SgF ItVAZelO2tqJChTID8wDrQqZc+U6OWHF/JJamWbQqyVtxRCmQugUuQ+pOxHhFosqOvsP jIE8tPiyrXPeOYp8rP2nqbuf56BIjiqT1NoYs69jqRycfeoxe7jL+Ldmg7dQwJ8jWQI6 R+bw== X-Gm-Message-State: ALyK8tKtXY5xx40lR5oG0wp2Bgv3OI4B6PRcuPdhqXBGkXY+/8zMnzROLabzXAF2dkkybNrvG68W5dcbMdSab4o/ X-Received: by 10.194.102.202 with SMTP id fq10mr1267553wjb.156.1466737282986; Thu, 23 Jun 2016 20:01:22 -0700 (PDT) MIME-Version: 1.0 Received: by 10.194.239.202 with HTTP; Thu, 23 Jun 2016 20:01:22 -0700 (PDT) In-Reply-To: References: <1466714880.88621749@apps.rackspace.com> From: Bob McMahon Date: Thu, 23 Jun 2016 20:01:22 -0700 Message-ID: To: David Lang Cc: dpreed@reed.com, make-wifi-fast@lists.bufferbloat.net, "cerowrt-devel@lists.bufferbloat.net" Content-Type: multipart/alternative; boundary=e89a8fb1f408bbb1ac0535fd6223 Subject: Re: [Make-wifi-fast] more well funded attempts showing market demand for better wifi 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: Fri, 24 Jun 2016 03:01:24 -0000 --e89a8fb1f408bbb1ac0535fd6223 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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 level= s > 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 design >> 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). Yo= u >>> 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 t= he >>> same problem - just digitize (ADC) a wider bandwidth and separate in th= e >>> digital domain. the only real issue on receive is equalization - if yo= u >>> receive two different signals at different receive signal strengths, th= e >>> 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 ar= e >>> nearly the same power. >>> >>> Equalization at transmit works very well when there is a central AP (as >>> in >>> cellular or normal WiFi systems). >>> >>> >>> >>> On Thursday, June 23, 2016 4:28pm, "Bob McMahon" < >>> bob.mcmahon@broadcom.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 eac= h >>>> >>> 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 chunks >>>>> would be a huge improvement, not many people are using them (yet), an= d >>>>> >>>> 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 en= d >>>>> >>>> up >>> >>>> needing multiple APs, or you have many stations, I expect that you wil= l >>>>> >>>> be >>> >>>> better off with more APs at lower power, each using different channels= . >>>>> >>>>> David Lang >>>>> >>>>> >>>>> >>>>> >>>>> On Thu, 23 Jun 2016, Bob McMahon wrote: >>>>> >>>>> Date: Thu, 23 Jun 2016 12:55:19 -0700 >>>>> >>>>>> From: Bob McMahon >>>>>> To: Dave Taht >>>>>> Cc: make-wifi-fast@lists.bufferbloat.net, >>>>>> "cerowrt-devel@lists.bufferbloat.net" >>>>>> >>>>>> Subject: Re: [Make-wifi-fast] more well funded attempts showing mark= et >>>>>> 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 isn= 't >>>>>> simultaneous, possibly costing more than any potential gain.) An A= P >>>>>> >>>>> 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 sit= e >>>>>> 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 >>>>>> >>>>> wrote: >>> >>>> >>>>>> On Wed, Jun 22, 2016 at 10:03 AM, Dave Taht >>>>>> >>>>> wrote: >>> >>>> >>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wif= i?ref=3Dbackerkit >>> >>>> >>>>>>> >>>>>>>> "Portal is the first and only router specifically engineered to cu= t >>>>>>>> through and avoid congestion, delivering consistent, >>>>>>>> high-performance >>>>>>>> WiFi with greater coverage throughout your home. >>>>>>>> >>>>>>>> Its proprietary spectrum turbocharger technology provides access t= o >>>>>>>> 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 wave2= ) >>>>>>> - >>>>>>> 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 comment >>>>>>> on >>>>>>> their kickstarter page. :) >>>>>>> >>>>>>> I'd have loved to have got in earlier (early shipments are this mon= th >>>>>>> apparently), but those were sold out. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wif= i/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 >>>>> >>>>> >>>>> >>>> >>> >>> >>> --e89a8fb1f408bbb1ac0535fd6223 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Thanks for the clarification. =C2=A0 Though now I'm co= nfused about how all the channels would be used simultaneously with an AP o= nly solution (which is my understanding of the kickstarter campaign.)=C2=A0=

Bob

On Thu, Jun 23, 2016 at 7:14 PM, David Lang <david@lang.hm> wrote:
I think he is meanin= g when one unit is talking to one AP the signal levels across multiple chan= nels will be similar. Which is probably fairly true.
<= div class=3D"h5">

David Lang

On Thu, 23 Jun 2016, Bob McMahon wrote:

Curious, where does the "in a LAN setup, the variability in [receive]<= br> signal strength is likely small enough" assertion come?=C2=A0 =C2=A0An= y specific
power numbers here? We test with many combinations of "signal strength=
variability" (e.g. deltas range from 0 dBm -=C2=A0 50 dBm) and per dif= ferent
channel conditions.=C2=A0 This includes power variability within the spatia= l
streams' MiMO transmission.=C2=A0 =C2=A0It would be helpful to have som= e 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.)=C2=A0 Power per bit usually trumps most other desi= gn
goals.=C2=A0 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, <dpreed@reed.com> 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).=C2=A0 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).=C2=A0 No= RF
problem.

Receiving multiple transmissions in different channels is pretty much the same problem - just digitize (ADC) a wider bandwidth and separate in the digital domain.=C2=A0 the only real issue on receive is equalization - if y= ou
receive two different signals at different receive signal strengths, the 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 are nearly the same power.

Equalization at transmit works very well when there is a central AP (as in<= br> cellular or normal WiFi systems).



On Thursday, June 23, 2016 4:28pm, "Bob McMahon" <bob.mcmahon@broadcom.com<= /a>>
said:

_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast
An AP per room/area, reducing the tx power (beacon range) has been my
approach and has scaled very well.=C2=A0 =C2=A0It does require some wires t= o each
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 <david@lang.hm> wrote:

Well, just using the 5GHz DFS channels in 80MHz or 160 MHz wide chunks
would be a huge improvement, not many people are using them (yet), and
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 end
up
needing multiple APs, or you have many stations, I expect that you will
be
better off with more APs at lower power, each using different channels.

David Lang




On Thu, 23 Jun 2016, Bob McMahon wrote:

Date: Thu, 23 Jun 2016 12:55:19 -0700
From: Bob McMahon <bob.mcmahon@broadcom.com>
To: Dave Taht <= dave.taht@gmail.com>
Cc: make-wifi-fast@lists.bufferbloat.net,
=C2=A0 =C2=A0 "cerowrt-devel@lists.bufferbloat.net"
=C2=A0 =C2=A0 <cerowrt-devel@lists.bufferbloat.net>
Subject: Re: [Make-wifi-fast] more well funded attempts showing market
demand
=C2=A0 =C2=A0 for better wifi


hmm, I'm skeptical.=C2=A0 =C2=A0To use multiple carriers simultaneously= is
difficult
per RF issues.=C2=A0 =C2=A0Even 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.=C2=A0 If this is just<= br> channel hopping, that needs coordination between both sides (and isn't<= br> simultaneous, possibly costing more than any potential gain.)=C2=A0 =C2=A0A= n 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 site seems
to indicate something beyond physics, at least the physics that I
understand.=C2=A0 Always willing to learn and be corrected if I'm
misunderstanding things.

Bob

On Wed, Jun 22, 2016 at 10:18 AM, Dave Taht <dave.taht@gmail.com>
wrote:

On Wed, Jun 22, 2016 at 10:03 AM, Dave Taht <dave.taht@gmail.com>
wrote:




https://www.= kickstarter.com/projects/portalwifi/portal-turbocharged-wifi?ref=3Dbackerki= t


"Portal is the first and only router specifically engineered to cut 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"<= br>
It sounds like they are promising working DFS support.


It's not clear what chipset they are using (they are claiming wave2) -<= br> 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 comment on
their kickstarter page. :)

I'd have loved to have got in earlier (early shipments are this month apparently), but those were sold out.




https://www.kicksta= rter.com/projects/portalwifi/portal-turbocharged-wifi/comments



--
Dave T=C3=A4ht
Let's go make home routers and wifi faster! With better software!
ht= tp://blog.cerowrt.org




--
Dave T=C3=A4ht
Let's go make home routers and wifi faster! With better software!
ht= tp://blog.cerowrt.org
_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast


_______________________________________________
Make-wifi-fast mailing list
M= ake-wifi-fast@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/make-wif= i-fast







--e89a8fb1f408bbb1ac0535fd6223--