
Facebook demonstrates record-breaking data rate using millimeter-wave technology - fforflo
https://code.facebook.com/posts/1197678800270377/facebook-demonstrates-record-breaking-data-rate-using-millimeter-wave-technology/
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autocorr
The article mentions that water vapor (humidity, fog, clouds, etc.) is the
most significant source of attenuation at these frequencies/wavelengths. This
is also the most important source of attenuation for radio astronomy
observations as well, along with atomic oxygen and ozone. This is why
millimeter-wave observatories have to be located in high altitude (> 10,000
feet) and dry locations, like the practical moonscape of the Atacama Plateau
in Chile where the Atacama Large Millimeter Array (ALMA) [1] is. ALMA is a
truly amazing instrument that's transforming modern astronomy, and they
operate between 4 mm to 0.350 mm (70 to 890 GHz).

If you want to see the effect of water vapor on these sorts of astronomical
observations, take a look at a nearby telescopes transmission calculator [2],
where it shows the percent of light that's transmitted from space to the
ground as a function of frequency. The "PWV" means precipitable water vapor,
and is the height of a column of water from precipitating all of the water in
a 1 centimeter square extended from the ground all the way up. The Atacama is
a super dry site, and 1 millimeter of PWV is routine there, but try putting in
100-1000 GHz with 0.5, 2, and 5 millimeters PWV that are typical of other
observatories!

[1] [http://www.almaobservatory.org/](http://www.almaobservatory.org/)

[2] [http://www.apex-
telescope.org/sites/chajnantor/atmosphere/tr...](http://www.apex-
telescope.org/sites/chajnantor/atmosphere/transpwv/)

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1024core
They conveniently tested it in SoCal.

> Specifically, rain and humidity could result in very high attenuation for
> terrestrial MMW links and could severely compromise their availability.

I imagine this will be useless in most equatorial parts of the world, and
probably even south-east US.

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jobu
It's unfortunate that they didn't delve deeper into the atmospheric
attenuation since the whole point of the project is to deliver internet from
UAVs. Seems like the next test should involve a foggy day in San Francisco
instead of a "air-to-ground bidirectional link".

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jdc0589
some tangentially related systems have fallbacks to different wavelengths that
penetrate better in sub-optimal conditions. I don't know if it's applicable
here, but I imagine it could be.

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danblick
So wait... is the defense industry involved in the Aquila project somehow? The
applications to defense/surveillance are obvious, and the aerospace technology
(if not the electronics) has been developed for the military/CIA/whatever.

Is Facebook getting government money to develop this? Or hoping for that as a
market? (Or is it, "We've already got one"?)

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londons_explore
By accepting military money, you usually have to sign off that you won't use
or sell the tech outside the USA. It usually comes under ITAR regulations too.

When you're Facebook, and your main target market for new connectivity
technology is Brazil, Indonesia, India, Malaysia, etc, that tends to be
problematic.

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daveguy
1mm wavelength is also known as 300 GHz carrier frequency.

The article states they use 30 - 300 GHz carrier with 2GHz bands. Definitely
line of sight technology. The graphic shows airplane use with a 30-50 km
range. Possibly usable in balloon relays too? (not satellite distances)

Links are in the 30-40 Gbps throughput range.

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jcoffland
> To put this in perspective, our demonstrated capacity is enough data to
> stream almost 1,000 ultra-high-definition videos at the same time.

Is FB considering getting into the TV market? This would be a way to enter the
market and compete with Dish, Time Warner, ATT, etc.

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debt
Facebook live seems to be doing pretty well so this seems likely.

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mrfusion
Would this work for wireless vr?

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ninkendo
That's exactly my thought. Short wave wireless to enable extremely high
throughput things like uncompressed video (as if it's a wireless HDMI cable)
as well as complex signals like accelerometer telemetry, etc mean this is a
perfect technology to make the Oculus wireless.

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daxfohl
Befuddling things: Trump defeating Clinton, Highly-disparaged MacBook Pro
outselling highly-acclaimed Surface Book in five days, Facebook (who uses
facebook anymore? who ever trusted them?) continually developing and deploying
the most awesome commercial tech in the world.

EDIT (Yes, to the comments, duh lots of people use facebook, buy disparaged
MBP the day it comes out and vote whatever. Some don't even use an oxford
comma. I just don't _get_ it.)

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mliker
that's news to me that MBP is outselling Surface. Also, at least 1 billion
people use Facebook so that must count for something.

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brisance
It's not a secret that Surface has not been selling well. Actually maybe it
is, because the numbers have to be derived by working backwards by dividing
revenue with ASP. I think it was something like a million units in the last
quarter.

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petr_tik
If this were sponsored and implemented by a trading firm there would be angry
comments about leeches living off honest people's incomes. minimising latency
to push another ladBible video into your eye balls is way more moral and
better for society apparently.

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johansch
Yeah, I'm going to believe that a company that basically lives on doing A/B
testing on engagement in a data sharing GUI (facebook.com) with a hobby in PR-
creating "hardware innovation" has suddenly beaten about a hundred thousand
world-class RF/EE engineers in e.g. Ericsson, Nokia-Siemens, Qualcomm, Huawei,
Alcatel-Lucent and Samsung.

The only way FB beats these guys is in marketing reach.

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wmf
Since those other companies don't talk much about what's in their labs, for
all we know they are already ahead of Facebook. Also, consider that Facebook
may have hired people with years or decades of experience from those very
companies.

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johansch
Well, this is going to get them to talk about their progress in this field, at
least. :)

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wmf
Maybe. Or maybe the legacy vendors will double down on their old "you need
standards compliance, backwards compatibility, support contracts, and a sales
channel" line.

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johansch
I think you're mixing things up.

a) These companies do love to brag about technical accomplishments. They each
have hundreds of product marketing and engineering people for this purpose
alone.

b) When they do sell, they will indeed double down on the things you
mentioned.

