Discussion:
closing up my make-wifi-fast lab
(too old to reply)
Dave Taht
2018-08-24 20:10:52 UTC
Permalink
All:

It is with some regret that I am announcing the closing of my
make-wifi-fast lab at the end of this month.

Over the years we have relied on the donation of lab space from
ISC.org, georgia tech, the LINCs, and the University of Karstadt and
elsewhere - but my main base of operation has always been the
"yurtlab", in a campground deep in the los gatos hills where I could
both experiment and deploy wifi fixes[0] at scale. CeroWrt, in
particular, was made here.

During the peak of the make-wifi-fast effort I rented additional space
on the same site, which at peak had over 30 routers in a crowded
space, competing. Which I (foolishly) kept, despite the additional
expense. Having heat in the winter and aircond in the summer was
helpful.

With ongoing donations running at $90/month[1] - which doesn't even
cover bufferbloat.net's servers in the cloud - my biggest expense has
been keeping the lab at lupin open at $1800/mo.

I kept the lab going through the sch_cake and openwrt 18.06 release
process, and I'm now several months behind on rent[3], and given how
things have gone for the past 2 years I don't see much use for it in
the future. Keeping it open, heated and dry in the winter has always
been a problem also. I'm also aware of a few larger, much better
equipped wifi labs that have thoroughly tested our "fq_codel for
wifi"[4] work that finally ends the "wifi performance anomaly". it's
in multiple commercial products now, we're seeing airtime fairness
being actually *marketed* as a wifi feature, and I kind of expect
deployment be universal across all mediatek mt76, and qualcomm ath9k
and ath10k based products in the next year or two. We won, big, on
wifi. Knocked it out of the park. Thanks all!

Despite identifying all kinds of other work[5] that can be done to
make wifi better, no major (or even minor) direct sponsor has ever
emerged[2] for the make-wifi-fast project. We had a small grant from
comcast, a bit of support from nlnet also, I subsidized what I did
here from other work sources, toke had his PHD support, and all the
wonderful volunteers here... and that's it.

Without me being able, also, to hire someone to keep the lab going, as
I freely admit to burnout and PTSD on perpetually reflashing and
reconfiguring routers...

I'm closing up shop here to gather enough energy, finances, and time
for the next project, whatever it is.

The make-wifi-fast mailing list and project will continue, efforts to
make more generic the new API also, and hopefully there's enough users
out there to
keep it all going forward without the kind of comprehensive testing I
used to do here.

If anyone feels like reflashing, oh, 30 bricked routers of 8 different
models, from serial ports (in multiple cases, like the 6 uap-ac-lites,
via soldiering on headers), I'll gladly toss all the extra equipment
in the lab in a big box and ship them to you. Suggestions for a
suitable donation target are also of interest.

The yurtlab has been an amazing, totally unique, unusual (and
sometimes embarrassing [6]) place to work and think, but it's time to
go.

Perhaps I'll convince my amazingly supportive landlord to let me leave
behind a plaque:

"On this spot bufferbloat on the internet and in WiFi was fixed, 2011-2018".

Sincerely,
Dave Taht

[0] https://lwn.net/Articles/705884/ "How we made wifi fast again"
[1] https://www.patreon.com/dtaht
[2] Like adrian chadd's infamous flameout - I too, give up on wifi.
There's gotta be some other tech worth working on. What we shipped is
"good enough" to carry a few years though.
[3] This is not a passive-aggressive request for help making rent next
month, given all the other problems I have, it's best to close up shop
while I look for a new gig.
[4] https://arxiv.org/pdf/1703.00064.pdf "ending the wifi anomaly"
[5] https://docs.google.com/document/d/1Se36svYE1Uzpppe1HWnEyat_sAGghB3kE285LElJBW4/edit#
[6] https://www.cringely.com/2012/10/01/clothing-may-be-optional-but-bufferbloat-isnt/
Michael Richardson
2018-08-25 18:02:00 UTC
Permalink
Thank you Dave for the amazing work you have done.
David P. Reed
2018-08-25 20:04:34 UTC
Permalink
WiFi is a bit harder than IP. But you know that.

I truly believe that we need to fix the phy/waveform/modulation space to really scale up open wireless networking capability. LBT is the basic bug in WiFi, and it is at that layer, melow the MAC.

I have tried for 20 years now to find a way to begin work at that project, by the way. There is also no major donor anywhere to be found for that work. Instead, any funds that seem to be appearing get attacked and sucked into projects that miss the point, being controlled by folks who oppose openness (e.g. WISPs wanting exclusive ownership of a market, such as so called SuperWiFi or whitespaces). I did once come close to a useful award when I was at MIT Media Lab, from NSF. But after the award, the funding was cut by 90%, leaving just enough to support a Master's thesis on co-channel sharing, using two 1st Gen USRPs. Using my own funds, spare time, and bubblegum and baling wire, I've slowly begun work on extra wideband FPGA based sounding-centric sharing in the 10 GHz Ham band. (500 MHz wide modulation), where I can self certify multiple stations in a network.

But the point is, I've failed, because there is less than zero support. There is active opposition, on top of cluelessness.

Paul Baran tried in 1993 to push forward a similar agenda, famously. 99% of his concepts died. Thanks to Apple, and lots of others, we got WiFi, barely. Industry hated that, and vow never to let that ever happen again.

So Dave, I salute you and Toke and the others. I salute Tim Shepard, who also moved the ball in his PhD thesis, only to hit the same wall of opposition.

It's so sad. We get shit like the "Obama band" proposed by PCAST, and are told to be thankful.

UWB failed miserably, too.

My advice to any young smart innovator: don't touch wireless unless you are working for an incumbent. Expect the incumbents and governments to close and destroy wireless innovation.

Really. You will be in a world of hurt, and NO ONE will support anything. Not even VCs.

Very sorry to say this. I had hoped Make WiFi Fast would have gone somewhere. I mourn its passing.

-----Original Message-----
From: "Dave Taht" <***@gmail.com>
Sent: Fri, Aug 24, 2018 at 4:10 pm
To: bloat-***@lists.bufferbloat.net, "bloat" <***@lists.bufferbloat.net>, "Make-Wifi-fast" <make-wifi-***@lists.bufferbloat.net>, cerowrt-***@lists.bufferbloat.net
Cc: bloat-***@lists.bufferbloat.net, "bloat" <***@lists.bufferbloat.net>, "Make-Wifi-fast" <make-wifi-***@lists.bufferbloat.net>, cerowrt-***@lists.bufferbloat.net
Subject: [Cerowrt-devel] closing up my make-wifi-fast lab

All:

It is with some regret that I am announcing the closing of my
make-wifi-fast lab at the end of this month.

Over the years we have relied on the donation of lab space from
ISC.org, georgia tech, the LINCs, and the University of Karstadt and
elsewhere - but my main base of operation has always been the
"yurtlab", in a campground deep in the los gatos hills where I could
both experiment and deploy wifi fixes[0] at scale. CeroWrt, in
particular, was made here.

During the peak of the make-wifi-fast effort I rented additional space
on the same site, which at peak had over 30 routers in a crowded
space, competing. Which I (foolishly) kept, despite the additional
expense. Having heat in the winter and aircond in the summer was
helpful.

With ongoing donations running at $90/month[1] - which doesn't even
cover bufferbloat.net's servers in the cloud - my biggest expense has
been keeping the lab at lupin open at $1800/mo.

I kept the lab going through the sch_cake and openwrt 18.06 release
process, and I'm now several months behind on rent[3], and given how
things have gone for the past 2 years I don't see much use for it in
the future. Keeping it open, heated and dry in the winter has always
been a problem also. I'm also aware of a few larger, much better
equipped wifi labs that have thoroughly tested our "fq_codel for
wifi"[4] work that finally ends the "wifi performance anomaly". it's
in multiple commercial products now, we're seeing airtime fairness
being actually *marketed* as a wifi feature, and I kind of expect
deployment be universal across all mediatek mt76, and qualcomm ath9k
and ath10k based products in the next year or two. We won, big, on
wifi. Knocked it out of the park. Thanks all!

Despite identifying all kinds of other work[5] that can be done to
make wifi better, no major (or even minor) direct sponsor has ever
emerged[2] for the make-wifi-fast project. We had a small grant from
comcast, a bit of support from nlnet also, I subsidized what I did
here from other work sources, toke had his PHD support, and all the
wonderful volunteers here... and that's it.

Without me being able, also, to hire someone to keep the lab going, as
I freely admit to burnout and PTSD on perpetually reflashing and
reconfiguring routers...

I'm closing up shop here to gather enough energy, finances, and time
for the next project, whatever it is.

The make-wifi-fast mailing list and project will continue, efforts to
make more generic the new API also, and hopefully there's enough users
out there to
keep it all going forward without the kind of comprehensive testing I
used to do here.

If anyone feels like reflashing, oh, 30 bricked routers of 8 different
models, from serial ports (in multiple cases, like the 6 uap-ac-lites,
via soldiering on headers), I'll gladly toss all the extra equipment
in the lab in a big box and ship them to you. Suggestions for a
suitable donation target are also of interest.

The yurtlab has been an amazing, totally unique, unusual (and
sometimes embarrassing [6]) place to work and think, but it's time to
go.

Perhaps I'll convince my amazingly supportive landlord to let me leave
behind a plaque:

"On this spot bufferbloat on the internet and in WiFi was fixed, 2011-2018".

Sincerely,
Dave Taht

[0] https://lwn.net/Articles/705884/ "How we made wifi fast again"
[1] https://www.patreon.com/dtaht
[2] Like adrian chadd's infamous flameout - I too, give up on wifi.
There's gotta be some other tech worth working on. What we shipped is
"good enough" to carry a few years though.
[3] This is not a passive-aggressive request for help making rent next
month, given all the other problems I have, it's best to close up shop
while I look for a new gig.
[4] https://arxiv.org/pdf/1703.00064.pdf "ending the wifi anomaly"
[5] https://docs.google.com/document/d/1Se36svYE1Uzpppe1HWnEyat_sAGghB3kE285LElJBW4/edit#
[6] https://www.cringely.com/2012/10/01/clothing-may-be-optional-but-bufferbloat-isnt/
_______________________________________________
Cerowrt-devel mailing list
Cerowrt-***@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel
Dave Taht
2018-08-25 21:22:09 UTC
Permalink
Post by David P. Reed
WiFi is a bit harder than IP. But you know that.
I truly believe that we need to fix the phy/waveform/modulation space to really scale up open wireless networking capability. LBT is the basic bug in WiFi, and it is at that layer, melow the MAC.
I have tried for 20 years now to find a way to begin work at that project, by the way. There is also no major donor anywhere to be found for that work. Instead, any funds that seem to be appearing get attacked and sucked into projects that miss the point, being controlled by folks who oppose openness (e.g. WISPs wanting exclusive ownership of a market, such as so called SuperWiFi or whitespaces). I did once come close to a useful award when I was at MIT Media Lab, from NSF. But after the award, the funding was cut by 90%, leaving just enough to support a Master's thesis on co-channel sharing, using two 1st Gen USRPs. Using my own funds, spare time, and bubblegum and baling wire, I've slowly begun work on extra wideband FPGA based sounding-centric sharing in the 10 GHz Ham band. (500 MHz wide modulation), where I can self certify multiple stations in a network.
But the point is, I've failed, because there is less than zero support. There is active opposition, on top of cluelessness.
Paul Baran tried in 1993 to push forward a similar agenda, famously. 99% of his concepts died.
Cite?

One of the things that bothers me about packet processing is that
Donald Davies (the oft uncredited other founder of the concept) wrote
11 volumes on this subject. So far as I know, those have vanished to
history.

Periodically, when I get stuck on something in this field, I fantasize
that scribbled in the margin of volume 9 was the solution to the
problem.
Post by David P. Reed
Thanks to Apple, and lots of others, we got WiFi, barely. Industry hated that, and vow never to let that ever happen again.
It really was a strange convolution of circumstances that led to wifi.
When i first got it working in 1998, metricom ruled the world. They
failed. After that, nobody thought it was feasible at scale until the
concept of a mac retry emerged to fix the packet loss problem, and APs
to provide a central clock (best we could do with the DSPs then). So
a window emerged (and yes, hugely driven by apple, but also by huge
popular demand for "wireless freedom") to put "buggy" wireless tech on
the crap 2.4 band in the hands of the people, it got established and
made the coffee shop a workplace, and bigcos attempting to wipe it out
(and largely, in the last few years, succeeding in dislodging it) have
had an uphill battle.

If metricom had succeeded, or the celluar folk got their
implementations working only a few years faster, it would be a very
different world.

(this history is all covered in my MIT preso here:
- david was at
that one)
Post by David P. Reed
So Dave, I salute you and Toke and the others. I salute Tim Shepard, who also moved the ball in his PhD thesis, only to hit the same wall of opposition.
Soooo many others involved, felix feitkau in particular comes to mind.

Still, I think fixing the "wifi anomaly" is the greatest achievement
of my career... and toke's hasn't even officially started yet! Someday
perhaps that will be worth a medal, or an small entry for us in
wikipedia.
Post by David P. Reed
It's so sad. We get shit like the "Obama band" proposed by PCAST, and are told to be thankful.
Let's not get started on that or whitespaces today.
Post by David P. Reed
UWB failed miserably, too.
I wish that could be resurrected.
Post by David P. Reed
My advice to any young smart innovator: don't touch wireless unless you are working for an incumbent. Expect the incumbents and governments to close and destroy wireless innovation.
I agree. Well, I do have some hope and interest in spacex's
constellation, but I remember teledesic's failure too well.
Post by David P. Reed
Really. You will be in a world of hurt, and NO ONE will support anything. Not even VCs.
Very sorry to say this. I had hoped Make WiFi Fast would have gone somewhere. I mourn its passing.
It's not dead, I'm just closing my lab.

In the document I cited for more wifi fixes, things like dynamically
scaling down the announced txop under contention, lowering retries,
offering a little less protection for packets when overloaded, a "tx
is almost done" interrupt, etc, are all things I expect vendors and
open source folk to try. I keep hoping minstrel-blues will land. Etc.
Outside the US there's still a lot of positive activity. Products like
eero and google wifi continue to sell like hotcakes, as well as tons
of cheaper gear, and iot, etc, etc.

And there's some good progress in 802.11ax.

fq_codel for wifi + these mods will make wifi continue to be more than
competitive with the upcoming 5G stuff.

But i don't need to be the one to implement or test them. I should
have shut things down when the shuttleworth grant didn't come through.
When you can no longer get up in the morning to work, nor able to hold
the wifi standard and related code in your head, it's time to move on.

It is bothersome to me that the ISPs don't seem to realize that their
business will fail unless they have good wifi, but the big ones are
out there merging with the LTE folk and don't care either.

Wifi's had a great run. I think here - with 5 years of work - we've
extended its life another 5 years - at least. Still, unless
applications emerge again that need good low latency (like vr) over
wifi, nothings going to drive those down further to compete with 5g.
Post by David P. Reed
-----Original Message-----
Sent: Fri, Aug 24, 2018 at 4:10 pm
Subject: [Cerowrt-devel] closing up my make-wifi-fast lab
It is with some regret that I am announcing the closing of my
make-wifi-fast lab at the end of this month.
Over the years we have relied on the donation of lab space from
ISC.org, georgia tech, the LINCs, and the University of Karstadt and
elsewhere - but my main base of operation has always been the
"yurtlab", in a campground deep in the los gatos hills where I could
both experiment and deploy wifi fixes[0] at scale. CeroWrt, in
particular, was made here.
During the peak of the make-wifi-fast effort I rented additional space
on the same site, which at peak had over 30 routers in a crowded
space, competing. Which I (foolishly) kept, despite the additional
expense. Having heat in the winter and aircond in the summer was
helpful.
With ongoing donations running at $90/month[1] - which doesn't even
cover bufferbloat.net's servers in the cloud - my biggest expense has
been keeping the lab at lupin open at $1800/mo.
I kept the lab going through the sch_cake and openwrt 18.06 release
process, and I'm now several months behind on rent[3], and given how
things have gone for the past 2 years I don't see much use for it in
the future. Keeping it open, heated and dry in the winter has always
been a problem also. I'm also aware of a few larger, much better
equipped wifi labs that have thoroughly tested our "fq_codel for
wifi"[4] work that finally ends the "wifi performance anomaly". it's
in multiple commercial products now, we're seeing airtime fairness
being actually *marketed* as a wifi feature, and I kind of expect
deployment be universal across all mediatek mt76, and qualcomm ath9k
and ath10k based products in the next year or two. We won, big, on
wifi. Knocked it out of the park. Thanks all!
Despite identifying all kinds of other work[5] that can be done to
make wifi better, no major (or even minor) direct sponsor has ever
emerged[2] for the make-wifi-fast project. We had a small grant from
comcast, a bit of support from nlnet also, I subsidized what I did
here from other work sources, toke had his PHD support, and all the
wonderful volunteers here... and that's it.
Without me being able, also, to hire someone to keep the lab going, as
I freely admit to burnout and PTSD on perpetually reflashing and
reconfiguring routers...
I'm closing up shop here to gather enough energy, finances, and time
for the next project, whatever it is.
The make-wifi-fast mailing list and project will continue, efforts to
make more generic the new API also, and hopefully there's enough users
out there to
keep it all going forward without the kind of comprehensive testing I
used to do here.
If anyone feels like reflashing, oh, 30 bricked routers of 8 different
models, from serial ports (in multiple cases, like the 6 uap-ac-lites,
via soldiering on headers), I'll gladly toss all the extra equipment
in the lab in a big box and ship them to you. Suggestions for a
suitable donation target are also of interest.
The yurtlab has been an amazing, totally unique, unusual (and
sometimes embarrassing [6]) place to work and think, but it's time to
go.
Perhaps I'll convince my amazingly supportive landlord to let me leave
"On this spot bufferbloat on the internet and in WiFi was fixed, 2011-2018".
Sincerely,
Dave Taht
[0] https://lwn.net/Articles/705884/ "How we made wifi fast again"
[1] https://www.patreon.com/dtaht
[2] Like adrian chadd's infamous flameout - I too, give up on wifi.
There's gotta be some other tech worth working on. What we shipped is
"good enough" to carry a few years though.
[3] This is not a passive-aggressive request for help making rent next
month, given all the other problems I have, it's best to close up shop
while I look for a new gig.
[4] https://arxiv.org/pdf/1703.00064.pdf "ending the wifi anomaly"
[5] https://docs.google.com/document/d/1Se36svYE1Uzpppe1HWnEyat_sAGghB3kE285LElJBW4/edit#
[6] https://www.cringely.com/2012/10/01/clothing-may-be-optional-but-bufferbloat-isnt/
_______________________________________________
Cerowrt-devel mailing list
https://lists.bufferbloat.net/listinfo/cerowrt-devel
--
Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619
David P. Reed
2018-08-26 12:26:12 UTC
Permalink
Baran: I got the year wrong. I remember it as 1993, but it was 1994 CNGN speech he made, which is resurrected here:
https://www.eff.org/pages/false-scarcity-baran-cngn-94

Paul was educated in EE, as was I. So radio made sense to him. Unlike kids brought up on the idea that bits are and must be physically discrete spatial and temporal mechanical things.

You know, one can have 1/10 of a bit of information, and store it in 1/10 of a bit of storage. Or transmit a symbol that passes through local noise and comes out the other side uncorrupted.

But kids trained in fancy CS depts. assume that bits require clear, empty, noiseless, pristine paths. Pure Bullshit. But CS and now many EE depts. and the FCC all proselytize such crap

So scarcity is inventedand sustained.

There is a reigning Supreme Court opinion, the law of the land, that says that there is by law a "finite number" of usable frequencies, and only one transmitter can be allowed to use it at a time. Like legislating that pi = 3 in a state, to make math easier.

Except it is totally designed to create scarcity. And the State/Industry Nexus maintains it at every turn. It's why lunatic economists claim that spectrum is a form of property that can be auctioned. Like creating property rights to each acre of the sea, allowing owners to block shipping by buying a connected path down the mid Atlantic.

We live in a Science Ignorant world. Intentionally. Even trained pH D. Engineers testify before the FCC to preserve these lies.

Yeah, I sound nuts. Check it out.


-----Original Message-----
From: "Dave Taht" <***@gmail.com>
Sent: Sat, Aug 25, 2018 at 5:22 pm
To: ***@deepplum.com
Cc: bloat-***@lists.bufferbloat.net, "bloat" <***@lists.bufferbloat.net>, "Make-Wifi-fast" <make-wifi-***@lists.bufferbloat.net>, cerowrt-***@lists.bufferbloat.net
Subject: Re: [Cerowrt-devel] closing up my make-wifi-fast lab
Post by David P. Reed
WiFi is a bit harder than IP. But you know that.
I truly believe that we need to fix the phy/waveform/modulation space to really scale up open wireless networking capability. LBT is the basic bug in WiFi, and it is at that layer, melow the MAC.
I have tried for 20 years now to find a way to begin work at that project, by the way. There is also no major donor anywhere to be found for that work. Instead, any funds that seem to be appearing get attacked and sucked into projects that miss the point, being controlled by folks who oppose openness (e.g. WISPs wanting exclusive ownership of a market, such as so called SuperWiFi or whitespaces). I did once come close to a useful award when I was at MIT Media Lab, from NSF. But after the award, the funding was cut by 90%, leaving just enough to support a Master's thesis on co-channel sharing, using two 1st Gen USRPs. Using my own funds, spare time, and bubblegum and baling wire, I've slowly begun work on extra wideband FPGA based sounding-centric sharing in the 10 GHz Ham band. (500 MHz wide modulation), where I can self certify multiple stations in a network.
But the point is, I've failed, because there is less than zero support. There is active opposition, on top of cluelessness.
Paul Baran tried in 1993 to push forward a similar agenda, famously. 99% of his concepts died.
Cite?

One of the things that bothers me about packet processing is that
Donald Davies (the oft uncredited other founder of the concept) wrote
11 volumes on this subject. So far as I know, those have vanished to
history.

Periodically, when I get stuck on something in this field, I fantasize
that scribbled in the margin of volume 9 was the solution to the
problem.
Post by David P. Reed
Thanks to Apple, and lots of others, we got WiFi, barely. Industry hated that, and vow never to let that ever happen again.
It really was a strange convolution of circumstances that led to wifi.
When i first got it working in 1998, metricom ruled the world. They
failed. After that, nobody thought it was feasible at scale until the
concept of a mac retry emerged to fix the packet loss problem, and APs
to provide a central clock (best we could do with the DSPs then). So
a window emerged (and yes, hugely driven by apple, but also by huge
popular demand for "wireless freedom") to put "buggy" wireless tech on
the crap 2.4 band in the hands of the people, it got established and
made the coffee shop a workplace, and bigcos attempting to wipe it out
(and largely, in the last few years, succeeding in dislodging it) have
had an uphill battle.

If metricom had succeeded, or the celluar folk got their
implementations working only a few years faster, it would be a very
different world.

(this history is all covered in my MIT preso here:
http://youtu.be/Wksh2DPHCDI - david was at
that one)
Post by David P. Reed
So Dave, I salute you and Toke and the others. I salute Tim Shepard, who also moved the ball in his PhD thesis, only to hit the same wall of opposition.
Soooo many others involved, felix feitkau in particular comes to mind.

Still, I think fixing the "wifi anomaly" is the greatest achievement
of my career... and toke's hasn't even officially started yet! Someday
perhaps that will be worth a medal, or an small entry for us in
wikipedia.
Post by David P. Reed
It's so sad. We get shit like the "Obama band" proposed by PCAST, and are told to be thankful.
Let's not get started on that or whitespaces today.
Post by David P. Reed
UWB failed miserably, too.
I wish that could be resurrected.
Post by David P. Reed
My advice to any young smart innovator: don't touch wireless unless you are working for an incumbent. Expect the incumbents and governments to close and destroy wireless innovation.
I agree. Well, I do have some hope and interest in spacex's
constellation, but I remember teledesic's failure too well.
Post by David P. Reed
Really. You will be in a world of hurt, and NO ONE will support anything. Not even VCs.
Very sorry to say this. I had hoped Make WiFi Fast would have gone somewhere. I mourn its passing.
It's not dead, I'm just closing my lab.

In the document I cited for more wifi fixes, things like dynamically
scaling down the announced txop under contention, lowering retries,
offering a little less protection for packets when overloaded, a "tx
is almost done" interrupt, etc, are all things I expect vendors and
open source folk to try. I keep hoping minstrel-blues will land. Etc.
Outside the US there's still a lot of positive activity. Products like
eero and google wifi continue to sell like hotcakes, as well as tons
of cheaper gear, and iot, etc, etc.

And there's some good progress in 802.11ax.

fq_codel for wifi + these mods will make wifi continue to be more than
competitive with the upcoming 5G stuff.

But i don't need to be the one to implement or test them. I should
have shut things down when the shuttleworth grant didn't come through.
When you can no longer get up in the morning to work, nor able to hold
the wifi standard and related code in your head, it's time to move on.

It is bothersome to me that the ISPs don't seem to realize that their
business will fail unless they have good wifi, but the big ones are
out there merging with the LTE folk and don't care either.

Wifi's had a great run. I think here - with 5 years of work - we've
extended its life another 5 years - at least. Still, unless
applications emerge again that need good low latency (like vr) over
wifi, nothings going to drive those down further to compete with 5g.
Post by David P. Reed
-----Original Message-----
From: "Dave Taht"
Sent: Fri, Aug 24, 2018 at 4:10 pm
Subject: [Cerowrt-devel] closing up my make-wifi-fast lab
It is with some regret that I am announcing the closing of my
make-wifi-fast lab at the end of this month.
Over the years we have relied on the donation of lab space from
ISC.org, georgia tech, the LINCs, and the University of Karstadt and
elsewhere - but my main base of operation has always been the
"yurtlab", in a campground deep in the los gatos hills where I could
both experiment and deploy wifi fixes[0] at scale. CeroWrt, in
particular, was made here.
During the peak of the make-wifi-fast effort I rented additional space
on the same site, which at peak had over 30 routers in a crowded
space, competing. Which I (foolishly) kept, despite the additional
expense. Having heat in the winter and aircond in the summer was
helpful.
With ongoing donations running at $90/month[1] - which doesn't even
cover bufferbloat.net's servers in the cloud - my biggest expense has
been keeping the lab at lupin open at $1800/mo.
I kept the lab going through the sch_cake and openwrt 18.06 release
process, and I'm now several months behind on rent[3], and given how
things have gone for the past 2 years I don't see much use for it in
the future. Keeping it open, heated and dry in the winter has always
been a problem also. I'm also aware of a few larger, much better
equipped wifi labs that have thoroughly tested our "fq_codel for
wifi"[4] work that finally ends the "wifi performance anomaly". it's
in multiple commercial products now, we're seeing airtime fairness
being actually *marketed* as a wifi feature, and I kind of expect
deployment be universal across all mediatek mt76, and qualcomm ath9k
and ath10k based products in the next year or two. We won, big, on
wifi. Knocked it out of the park. Thanks all!
Despite identifying all kinds of other work[5] that can be done to
make wifi better, no major (or even minor) direct sponsor has ever
emerged[2] for the make-wifi-fast project. We had a small grant from
comcast, a bit of support from nlnet also, I subsidized what I did
here from other work sources, toke had his PHD support, and all the
wonderful volunteers here... and that's it.
Without me being able, also, to hire someone to keep the lab going, as
I freely admit to burnout and PTSD on perpetually reflashing and
reconfiguring routers...
I'm closing up shop here to gather enough energy, finances, and time
for the next project, whatever it is.
The make-wifi-fast mailing list and project will continue, efforts to
make more generic the new API also, and hopefully there's enough users
out there to
keep it all going forward without the kind of comprehensive testing I
used to do here.
If anyone feels like reflashing, oh, 30 bricked routers of 8 different
models, from serial ports (in multiple cases, like the 6 uap-ac-lites,
via soldiering on headers), I'll gladly toss all the extra equipment
in the lab in a big box and ship them to you. Suggestions for a
suitable donation target are also of interest.
The yurtlab has been an amazing, totally unique, unusual (and
sometimes embarrassing [6]) place to work and think, but it's time to
go.
Perhaps I'll convince my amazingly supportive landlord to let me leave
"On this spot bufferbloat on the internet and in WiFi was fixed, 2011-2018".
Sincerely,
Dave Taht
[0] https://lwn.net/Articles/705884/ "How we made wifi fast again"
[1] https://www.patreon.com/dtaht
[2] Like adrian chadd's infamous flameout - I too, give up on wifi.
There's gotta be some other tech worth working on. What we shipped is
"good enough" to carry a few years though.
[3] This is not a passive-aggressive request for help making rent next
month, given all the other problems I have, it's best to close up shop
while I look for a new gig.
[4] https://arxiv.org/pdf/1703.00064.pdf "ending the wifi anomaly"
[5] https://docs.google.com/document/d/1Se36svYE1Uzpppe1HWnEyat_sAGghB3kE285LElJBW4/edit#
[6] https://www.cringely.com/2012/10/01/clothing-may-be-optional-but-bufferbloat-isnt/
_______________________________________________
Cerowrt-devel mailing list
https://lists.bufferbloat.net/listinfo/cerowrt-devel
--
Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619
Jonathan Morton
2018-08-27 06:26:32 UTC
Permalink
Curious to how LBT can be solved at the PHY level and if the potential solution sets preserve the end to end principle.
The usual alternatives include TDM, usually coordinated by a master device (eg. the AP); full-duplex operation via diplexers and/or orthogonal coding; and simply firing off a packet and retrying with exponential backoff if an acknowledgement is not heard.

TDM and diplexing are already used by both DOCSIS and LTE. They are proven technology. However, in DOCSIS the diplexing is greatly simplified by the use of a copper channel rather than airwaves, and in LTE the diplexer is fitted only at the tower, not in each client - so the tower can transmit and receive simultaneously, but an individual client cannot, but this is still useful because there are many clients per tower. Effective diplexers for wireless are expensive.

Orthogonal coding is already used by GPS and, in a rather esoteric form, by MIMO-grade wifi. IMHO it works rather better in GPS than in wifi. In GPS, it allows all of the satellites in the constellation to transmit on the standard frequency simultaneously, while still being individually distinguishable. The data rate is very low, however, since each satellite's signal inherently has a negative SNR (because there's a dozen others shouting over it) - that's why it takes a full minute for a receiver to get a fix from cold, because it simply takes that long to download the ephemeris from the first satellite whose signal is found.

A future version of wifi could reasonably use TDM, I think, but not diplexing. The way this would work is that the AP assigns each station (including itself) a series of time windows in which to transmit as much as they like, and broadcasts this schedule along with its beacon. Also scheduled would be windows in which the AP listens for new stations, including possibly other nearby APs with which it may mutually coordinate time. A mesh network could thus be constructed entirely out of mutually coordinating APs if necessary.

The above paragraph is obviously a giant handwave...

- Jonathan Morton
Jonathan Morton
2018-08-27 07:52:27 UTC
Permalink
How can a centralized device predict the many "end stations'" network demand in its time scheduling?
DOCSIS does it by initially giving stations a tiny window into which to send requests for time, which are granted by the head-end. This introduces some latency. Further requests for time can be appended to a real transmission, which helps efficiency slightly.

Developing from that model, an AP might initially divide time evenly between stations, allowing them to send single large packets or several small packets without an explicit request for time - this is good for latency. Along with that packet, the station could indicate to the AP that it has a queue of packets waiting, and the AP would take that into account when producing its next schedule. It would also take into account its own queue.

It may be possible to combine TDM with orthogonal coding. Here the AP monitors the received signal strength of its stations, and instructs them to change power so as to minimise the difference between them. This maximises the SNR for each, should two transmit simultaneously. The tradeoff, of course, is that orthogonal coding permits a reduction in waiting to transmit, but requires a reduction in data rate during the transmission. I'm sure other people have better data on that than I do.

- Jonathan Morton
Jonathan Morton
2018-08-27 19:45:56 UTC
Permalink
I guess my question is can a WiFi transmitting device rely on primarily energy detect and mostly ignore the EDCA probability game and rather search for (or predict) unused spectrum per a time interval such that its digital signal has enough power per its observed SNR? Then detect "collisions" (or, "superposition cases" per the RX not having sufficient SINR) via inserting silent gaps in its TX used to sample ED, i.e. run energy detect throughout the entire transmission? Or better, no silent gaps, rather detect if there is superimposed energy on it's own TX and predict a collision (i.e. RX probably couldn't decode its signal) occurred? If doable, this seems simpler than having to realize centralized (or even distributed) media access algorithms a la, TDM, EDCA with ED, token buses, token rings, etc. and not require media access coordination by things like APs.
The software might be simpler, but the hardware would need to be overspecified to the point of making it unreasonably expensive for consumer devices.

Radio hardware generally has a significant TX/RX turnaround time, required for the RX deafening circuits to disengage. Without those deafening circuits, the receivers would be damaged by the comparatively vast TX power in the antenna.

So in practice, it's easier to measure SNR at the receiver, or indirectly by observing packet loss by dint of missing acknowledgements returned to the transmitter.

- Jonathan Morton
Jonathan Morton
2018-08-27 22:37:24 UTC
Permalink
Indeed - and conversely, there may be interference that the transmitter can
hear clearly but which is irrelevant to the intended receiver. In that
case, any form of LBT will be needlessly conservative.

- Jonathan Morton

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