[Cerowrt-devel] [Make-wifi-fast] more well funded attempts showing market demand for better wifi

David Lang david at lang.hm
Fri Jun 24 01:19:50 EDT 2016 

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 
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 <bob.mcmahon at broadcom.com>
> To: David Lang <david at lang.hm>
> Cc: dpreed at reed.com, make-wifi-fast at lists.bufferbloat.net,
>     "cerowrt-devel at lists.bufferbloat.net"
>     <cerowrt-devel at lists.bufferbloat.net>
> Subject: Re: [Make-wifi-fast] more well funded attempts showing market demand
>     for better wifi
> 
> 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 <david at lang.hm> wrote:
>
>> I think he is meaning when one unit is talking to one AP the signal levels
>> 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, <dpreed at 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).  You
>>>> 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 the
>>>> digital domain.  the only real issue on receive is equalization - if you
>>>> 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
>>>> cellular or normal WiFi systems).
>>>>
>>>>
>>>>
>>>> On Thursday, June 23, 2016 4:28pm, "Bob McMahon" <
>>>> bob.mcmahon at broadcom.com>
>>>> said:
>>>>
>>>> _______________________________________________
>>>>> Make-wifi-fast mailing list
>>>>> Make-wifi-fast at 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 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 at 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 at broadcom.com>
>>>>>>> To: Dave Taht <dave.taht at gmail.com>
>>>>>>> Cc: make-wifi-fast at lists.bufferbloat.net,
>>>>>>>     "cerowrt-devel at lists.bufferbloat.net"
>>>>>>>     <cerowrt-devel at lists.bufferbloat.net>
>>>>>>> Subject: Re: [Make-wifi-fast] more well funded attempts showing market
>>>>>>> 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 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.  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 at gmail.com>
>>>>>>>
>>>>>> wrote:
>>>>
>>>>>
>>>>>>> On Wed, Jun 22, 2016 at 10:03 AM, Dave Taht <dave.taht at gmail.com>
>>>>>>>
>>>>>> wrote:
>>>>
>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wifi?ref=backerkit
>>>>
>>>>>
>>>>>>>>
>>>>>>>>> "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"
>>>>>>>>>
>>>>>>>>> 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 month
>>>>>>>> apparently), but those were sold out.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>> https://www.kickstarter.com/projects/portalwifi/portal-turbocharged-wifi/comments
>>>>
>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>>> Dave Täht
>>>>>>>>> Let's go make home routers and wifi faster! With better software!
>>>>>>>>> http://blog.cerowrt.org
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Dave Täht
>>>>>>>> Let's go make home routers and wifi faster! With better software!
>>>>>>>> http://blog.cerowrt.org
>>>>>>>> _______________________________________________
>>>>>>>> Make-wifi-fast mailing list
>>>>>>>> Make-wifi-fast at lists.bufferbloat.net
>>>>>>>> https://lists.bufferbloat.net/listinfo/make-wifi-fast
>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>> Make-wifi-fast mailing list
>>>>>> Make-wifi-fast at lists.bufferbloat.net
>>>>>> https://lists.bufferbloat.net/listinfo/make-wifi-fast
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>>
>

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