
Lowly DSL poised for gigabit speed boost - anigbrowl
http://www.cnet.com/news/lowly-dsl-broadband-poised-for-gigabit-speed-boost/
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stephen_g
The main issues with this is the fact that the speeds reduce quite
spectacularly as you get further from the node - while at 50m you might get
~400 to 800Mbps (depending on the quality of the lines), by the time you're
several hundred meters away you're back to the tens of megabits...

It's got to do with how the low quality telephone cables attenuate high
frequencies. They're typically thin wire (0.4 or 0.64mm gauge) designed for a
voice signal with a bandwidth in the kHz ranges, and then these DSL
technologies use tens to hundreds of MHz, which works to some extent over
shorter distances but the higher frequency you go, the more quickly attenuate
over longer distances.

Then you have electromagnetic interference between different subscriber's
lines, which can make a huge dent in performance (literally as high as
40-50%). Vectoring is a technology that tries to model the noise and send
signals to cancel it out to reduce this. It's fairly effective, but not
completely.

What you get is the requirement to basically have a node, fed with fibre and
electricity (unless they're back-powered from houses, which was suggested for
G.fast) that only services a dozen or so houses. With the cost of the capital
works required, it's debatable whether it's not worth spending the ~$800-$1200
per house (this is actuals from the Australian NBN rollout) to just complete
the fibre all the way, which could then in the future be upgraded to 10Gbit
without any capital works (just swapping the terminating hardware in the
exchange and at the customer premises - no requirement to touch any of the
cabling).

~~~
pwarner
The fun thing is fiber at rates beyond 10 Gbps over long distances require
just as many DSP tricks as DSL. For example
[http://www.lightwaveonline.com/articles/2014/09/fujitsu-
ntt-...](http://www.lightwaveonline.com/articles/2014/09/fujitsu-ntt-nec-
send-400g-across-10-000-km.html)

~~~
tacticus
There is a slight difference between thousands of kms and 10s of KMs

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Jgrubb
So nice to read about all this exciting network technology that won't matter
at all because CenturyLink and Verizon et al are still going to artificially
throttle the services I would use them for.

Thank you to the engineers for still trying, though.

~~~
mikeash
I moved a couple of years ago. At my old place, I had the choice between cable
and DSL. Verizon was the DSL provider, and the best they could give me was
1.5Mbps. I went with cable.

At my new place, I have the choice between cable and fiber. Verizon is the
fiber provider, and they'll happily sell me up to 500Mbps if I want to pay for
it, and they deliver. That's symmetrical, too, as of a couple of months ago.

I'm not a fan of big ISPs, but I don't think it's quite as bad as you say
either.

~~~
lern_too_spel
He's referring to [http://blog.level3.com/open-internet/verizons-accidental-
mea...](http://blog.level3.com/open-internet/verizons-accidental-mea-culpa/).
Verizon will happily take your money to give you 500 Mbps to anything on their
own network, but for anything on the internet at large, be prepared to wait
during peak traffic hours.

~~~
mikeash
I've had occasional problems with YouTube (I don't use Netflix) so it's true
that this is a real problem, but for 99% of what I do, I'm able to max out my
300Mbps with no problem as long as the other end can do it too.

I don't mean to cheerlead for Verizon here, but the fact is that higher speeds
aren't made pointless, even if they're not _quite_ as good as they could be.

~~~
lern_too_spel
It's peak usage traffic that's affected. During the day, when nobody is using
the network, it should be pretty zippy. In the evening, their connections to
the internet will be congested, and I wouldn't be surprised if you had trouble
with 1 Mbps streams. It's ludicrous that they charge for 300 Mbps service
while actually providing measurably worse service than 20 Mbps Sonic DSL, and
they have gotten away with it.

~~~
mikeash
I occasionally notice trouble with YouTube at peak hours, but never anywhere
else. So while it's not ideal, it's still really good.

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aphistic
(*) If you're within 50m of the fiber.

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timthorn
One of the big hurdles that FTTP faces is getting the fibre into the
customer's house. Perfectly doable, but expensive to achieve. G.Fast enables
the upgrade to ~gigabit speeds without needing to drill through brick walls
and/or ensure that the customer is at home.

~~~
sjtrny
I am happy to be home at anytime if it means I get Fibre. As OP mentioned
these technologies are only really suitable in specific cases such as in
apartment buildings. In a suburban environment no one will ever see gigabit
speeds.

~~~
timthorn
You might well be a reliable customer and at home for the engineer visit, but
not all of the general population is quite so helpful!

The head of BT's R&D group gave a presentation in Cambridge yesterday. Slide
15 of his deck shows real world speeds ranging from 700Mbps-1000Mbps for
vectored G.Fast obtained in a live suburban environment:
[http://cwbackoffice.co.uk/Presentation/PrestigeLecture_21.10...](http://cwbackoffice.co.uk/Presentation/PrestigeLecture_21.10.14_TimWhitley.pdf)

~~~
sjtrny
I think those values are optimistic.
[http://en.wikipedia.org/wiki/G.fast#Performance](http://en.wikipedia.org/wiki/G.fast#Performance)
says that the speeds reported are actually shared between uplink and downlink.
Furthermore this was in laboratory conditions. Most people have copper lines
that are at least 20 years old.

One way to get around customers not being home is to make Fibre rollout opt-
out. Then only wire Fibre to the outside wall of every customers house. At a
time that suits them they can organise a tech to come out and complete the
connection.

~~~
timthorn
Those values are measured in real-world conditions, not the lab - they've
deployed to 3 homes in a housing estate near Ipswich from one distribution
point - though I believe that you are correct in saying that they are
aggregate throughput.

You can't dig up peoples' gardens without permission! That suggestion also
requires 2 separate truck-rolls, and still relies on someone being home for
the appointment to complete the connection. Of course it can be done - is
being done - but relying on the customer increases the cost.

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jpollock
I was surprised to learn that mobile networks use a lot of xDSL links to their
base stations. They're faster to get provisioned than a traditional data link.
So, anything which increases bandwidth in DSL will benefit mobile networks.

[http://www.ericsson.com/ericsson/corpinfo/publications/revie...](http://www.ericsson.com/ericsson/corpinfo/publications/review/2009_02/files/Backhaul.pdf)

~~~
Aloha
not on a 200m loop - that's only 600 feet or so, with where most cell sites
are, you might as well just trench the fiber in the last little bit. I know
that 'yellow' carrier just extended fiber to most of their network footprint,
with microwave serving the rest.

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PaulHoule
I think this is an exciting development for apartment dewellers in places like
the Netherland and San Francisco, but the DSL problem in America is in rural
areas where even 6MBps is possible.

~~~
bluedino
I live across the street from the main AT&T office in my town and I can't get
> 1.5mb

~~~
lanaius
My parents have been capped at 1.5 mbps (in practice closer to 768 mbps) since
around 2003, and they're about 1/3 to 1/2 a mile away from the closest box.
Over the years I've made multiple requests that resulted in improved line
quality (change in PoP wiring, removed some home outlets with corroded
contacts, remove bridge taps on the lines) but Ameritech-SBC-AT&T have never
offered a better speed. They abandoned DSL in favor of U-Verse which, for
rural locations, is of absolutely no use since they're never going to run
fiber out to those semi-remote and remote DSLAMs. I wish something like G.fast
would be useful in the US but the locations for which the distance isn't an
issue are generally locations which have already been better served for a
decade or longer by another technology than copper (cable, FTTH, FTTN, even
Wireless in some cases).

~~~
kileywm
If your parents are 1/3 to 1/2 of a mile away from the closest box with those
speeds, then it's likely the 'box' is a crossbox (wiring junction) instead of
a DSLAM (networking card). Where the DSLAM is that is feeding that crossbox...
well that could be much further.

If the loop length is .34-.5 miles (which is quite good) with no impedance
mismatch or bridge taps or other various copper faults, then you would/should
be able to sustain 10+ Mbps on an ADSL2+ connection.

My guess is that the distance is further than it seems, and the line may not
have been reconditioned from phone to internet purposes.

Anyway I bring it up because distance is the biggest determinant of bandwidth
when it comes to copper, and if the distance is great then there is little
that fixing copper faults can do to improve internet speeds at your parents'
place.

~~~
lanaius
It should be a DSLAM (by now) as it was a regular junction that was replaced
and added to with one of the larger white DSLAM boxes. I could be mistaken
though, so that's a fair thing to point out.

~~~
kileywm
If there is a DSLAM right next to the crossbox, then these are the two
possibilities:

[1] (Common and very likely) The DSLAM they installed there is a fiber node
and feeds only VDSL over < 50 ft wire to the crossbox. ADSL also feeds into
the crossbox, but not from the new DSLAM. It still travels from the CO
(central office) and may still be 1-2 miles of wire away.

[2] (Uncommon and less likely) The DSLAM has VDSL and ADSL cards in it. In
this situation the DSLAM can support high speed VDSL to very close residents
and ADSL to further residents. The CO is no longer the source of ADSL signal,
and this is typically a nice reduction in loop length for people.

In your shoes, I'd get in touch with the ISP and see if you're CO fed or not.
If you're CO fed, there's little that can be done to improve the speeds =(.
You could ask if it's possible to do pair bonding to improve your speeds. Just
beware, switching to pair bonding means you'd need to lease/purchase a new
modem that can do bonding and the ISP would have to roll a truck to wire up
the 2nd pair.

Hope that helps!

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nazgulnarsil
One of the issues here is that many of these DSL breakthroughs are under ideal
conditions. One of the things slowing down DSL is the poor quality of the
wiring in many older homes (read: most homes).

~~~
Pxtl
I'd wager the phone cable is hooking to a WiFi router, so just stick the
router right next to the first phone junction.

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higherpurpose
I'll believe that when I see it (not the technology - that actually has a
higher chance of happening than DSL providers offering 1Gbps for a reasonable
price).

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Aloha
This is of great benefit for in building wiring - I'd love to see a table for
speed/distance, that'd give you a better idea of real world practicality. OSP
is honestly in pretty decent shape in most of the US, its a lack of careful
conditioning and poor records that causes most DSL issues.

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andygambles
And here in the UK the Gov have labelled superfast broadband as being greater
than 2mbps. The speed it takes for rollout of FTTC means we will see this in
2020 when we are all using 6G mobile networks at 10Gbps anyway.

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sriku
The significant question here is whether providers will offer this both ways -
i.e. _symmetrical_ uplink/downlink. If the asymmetry is going to persist, then
game over for DSL, welcome fibre.

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dazs1on
meanwhile in singapore you get an uncapped speed(above and beyond 1 gbit) for
half the price i pay for 15 mbit

~~~
adventured
Singapore is an extremely small, very rich country with hyper population
density. I don't see how that's a great example. They should have some of the
fastest Internet speeds on the planet.

How about in Russia, Canada, US, China, Brazil, Australia, India, Argentina,
Kazakhstan, Algeria, Congo, Saudi Arabia, Mexico, Indonesia, Sudan, Libya,
Iran, Mongolia, Peru, Chad, Niger, Angola?

Those are the largest countries in the world. Presents a drastically different
challenge wouldn't you say?

~~~
jquery
> Singapore is an extremely small, very rich country with hyper population
> density. I don't see how that's a great example. They should have some of
> the fastest Internet speeds on the planet.

Why shouldn't at least New York and Bay Area be comparable? Rich and hyper-
dense.

\--submitted from an 4 megabit connection in SF.

~~~
rhino369
New York and the Bay Area aren't all that dense by major city standards.

But the real reason for the difference isn't really density. It is government
telecom policy. The countries that deployed fiber have, for the most part,
either heavily subsidized it via direct subsidies or tax breaks. In Sweden's
case, for example, forced state run utilities to build the backbone for the
telecoms.

The US expects the telecom investment to be 100% privately funded. That means
it has to be profitable enough to attract capital investments.

Unlike say Sweeden, were everyone has to use the single telecom provider's
network, in the US there is no such mandate. Verizon's FIOS network has to
compete with the cable companies network (which is vastly cheaper). Fios is
only getting around 25% of people who have potential access to sign up. The
Singapore network probably gets 90% or more.

If you really want fiber in the entire USA. Give Verizon, ATT, Century Link,
and the other incumbent local loop carriers huge tax incentives to do it.
Otherwise it'll happen slowly when people are willing to pay a premium for
higher speed.

