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New Look at ADSL2
genrader writes "broadbandreports.com just posted a news article which had an interesting story about the new ADSL2, which should be approved in 2003. They say it should be backward compatible with current hardware. It seems pretty interesting. ISP-Planet has the featured in-depth look at it, so you might want to see if it is of any intrest to you."
Sure, ADSL2 is faster, but how many of us are running our DSL lines at close to the max speed now? I can do 3+ Mb/s on this line, but only get to use 640 Kb/s. New technology that allows me to go faster, yeah that'll come in handy! If it worked at a much longer range it might be useful for some who are out of range now, but it really isn't much of an advance there either. So why should we care, this is like getting excited because Macs are shipping with a gigabit ethernet port when your office is running on a shared 10 mbit hub!
The increases in performance and range are pretty minimal. An additional 50kbps and 600ft of range isn't all that impressive, although the fact that it is backwards compatible with some existing hardware is semi-promising.
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Anyway, here's some extra info on ADSL2, or G.bis that i dug up:
http://www.aware.com/products/DSL/gbisadsl2.htm
http://www.convergedigest.com/Silicon/siliconarti
http://www.dslprime.com/a/adsl21.pdf(sorry about the pdf)
Great one more thing for the telcos to screw up. I'm sure that ADSL2 means 2x the wait and 2x the cost. I'm already looking at my calendar and setting aside a week to wait for them to show up. I'm sure they'll have to make twice as many trips out for line tests and the techs will be twice as ignorant of the technology involved. In Soviet Russia, I bet they get it installed quicker.
Look - new, faster stuff that won't be available in my neighborhood!
"The real problem is that the guys in charge have so very little motivating them to implement new and better things..."
.. like 15-30 miles from the telco ...
"Why bother?
Do we actually think for a moment that US telcos will adopt anything decent? Please...if it's not a patented US currency printing press or a customer cornholing machine...they won't be interested."
And even better...
"For example, on longer phone lines, ADSL2 will provide a data rate increase of 50 kbps--a significant increase. This data rate increase also produces an increase in reach of about 600 feet, which translates to an increase in coverage area of about six percent, or 2.5 square miles."
Wooohooo...a whopping 50kbps, 600 feet...WOW...totally worthless! In about a zillion years they'll have enough range to reach me at 60,000ft from the nearest CO. Hell, telcos can even measure their copper runs accurate to 600ft. I'm serviced at my office at an actual copper length of 19,200ft...while Verizon originally estimated under 15,000ft.
Wow!
It's good for a total of 8,000 feet! Instead of screwing around with short length technologies, why don't they develope something that has far better range
Quidquid latine dictum sit altum viditur
First of all, the story at broadbandreports.com is nothing but a short blurb about the story at ISP-Planet.
Second, the people who posted comments didn't read it. Not sure what the original author meant by a 50kbps increase, but earlier in the article he mentions a doubling of the frequency used resulting in a doubling of the downstream bandwidth. That's significant to me.
I just signed up for a 12Mbit line here in Tokyo.
(I'm upgrading from 8Mbit - the 12 is actually a cheaper plan.)
Regular DSL, IIRC. Used the 30 year old wiring in my place, no problem.
Even on the 8, I've had Internet downloads stream in at better than 1500K.
A year or two ago, Japan was *way* behind in internet access - I was using ISDN (cheap here) and I was a bit of a rare case. Most people used dialup.
So what's really holding DSL back over there? I'd bet the reasons were more economic than engineering.
Just a thought,
Jim
-- My Weblog.
I can't see that this would be all that useful. While a very cool upgrade for the sake of very cool upgrades, how is it all that great?
My DSL connection is very high speed. I feel no net slowdown when listening to Shoutcast Radio on a 128Kbps station; even though I'm eating up 1/4 of my downlink, only rarely does it actually have an effect.
The slowdowns are at the other end. The servers are overloaded; its their T3s that need to be upgraded. Although 500,000 hits in the period of an hour would swamp anything, I suppose.
So while this idea has merit, a whole bunch of other stuff would have to improve too if this is to be particularly useful.
Warning: Poster of this comment is a nerd. Just like everybody else here.
I mean honestly, I am sure that someone here can explain why DSL is fundamentally going to be limited as far as bandwidth and range goes. Copper is a very lossy media, and we already have better stuff out there like fiber optic, and even fiberless communications versus mutliplexed wavelengths (eg Lucent) or even things such as wireless LAN's (although with a more limited range).
The point is that what we need is something that is a complete departure from the paradigm of cable and DSL modems. That is the only thing that is going to allow us to ALL have broadband, and for the cheap, at very high speeds. I have no idea what it will be, though I think it will have to be some wireless technology. Until then, I think we are going to be stuck in this rut of a small number of broadband users who get to use a flawed and unsatisfactory system (except for those that just surf and check e-mail) due to speed constraints and whatnot.
Any ideas of a new system, or how long one might take to engineer? I'm guessing around 20-35 years.
Remember your high-school geometry , area of a circle is pi(r^2)
So the 6% ( ? ) increase in range translates to a more than 12% increase in coverage area. It's not as small as first it appears.
The fact that no one understands you doesn't mean you're an artist.
The article says that there WILL be an increase in service radius by 6% from the telco loop to your home. Which translates into bigger area of service (~2.5 mi.)
Live for the present, learn from the past, and dream of the future!
Well this is all well and good, but lets keep in mind that dsl is expensive to roll-out, what is motivating the company I work for to go out and purchase this *new* wonderful equipment which is going to require upgrades at least in the DSLAM's / ATM switches, nothing is just "hook it in and it works", ever.
It's wonderful that they claim these super fast speeds, but what's the point right now? My company already has equipment in place to offer a few megabit to the home user, but we don't currently offer speeds faster then 768/768. Why? Because the demand isn't there, period. A few geeks here and there, or maybe a business or two, but most business that need something faster then 768 symetric are going to go with another dedicated telco soltion such as a T-1, or a DS3.
I'm happy that we have these wonderful systems, that promise super fast bandwidth, and I'm not saying I don't believe the speeds, I'm just skeptical that we're going to see them hitting the market anytime soon because phone companies aren't eager to roll them out, keep in mind they're all still trying to re-coup the costs to roll out the network in the first place.
All this stuff is down at the physical layer. There's no mention of the higher layers; apparently we're still stuck with PPPoE, a login mechanism, and client software.
The big win with this thing will be the improved diagnostics, along with slightly better noise immunity and the power-save modes.
Let's call the existing distance (not specified in the article), "r". So the original and new coverage areas ought to be (in terms of feet):
orig_coverage = pi * r * r
new_coverage = pi * (r + 600) * (r + 600)
The difference between these is claimed to be 2.5 square miles. Since there's 5280 feet in a mile, the difference between these two is supposed to be:
new_coverage - orig_coverage = 2.5 * 5280 * 5280
So, putting these together, and multiplying out the (r+600)*(r+600) part, it ought to be possible to deduce the original radius: ....adding some parens to make it easier to read
(pi * r * r) + (pi * 2 * 600 * r) + (pi * 600 * 600) - (pi * r * r) = 2.5 * 5280 * 5280
So, luckily the r squared terms subtract each other out, so this little bit of math won't requiring using a quadratic equation. Subracting the constant, it turns into:
pi * 2 * 600 * r = 2.5 * 5280 * 5280 - pi * 600 * 600
Now for anyone reading this far who's good at basic algerba, I'm going to appologize for yet a couple more simple steps spelled out....
r * 3769.9 = 69696000 - 1130972.4
r = 68565027.6 / 3769.9
r = 18187.5
So it looks like existing DSL goes 3.44 miles, and this new one goes 3.56 miles, and the increase from 37.276 square mile to 39.776 square miles really is 6% (actually 6.7%).
So it does really work out, and the existing DSL distance of 3.44 miles sounds reasonable.
Of course, it's all a moot point if the FCC allows the cable and baby bells to lock out competition. The only reason almost anyone has DSL within a 3.44 mile radius is because AT&T started rolling out high speed cable. What this new DSL _really_ needs (other than a real increase in distance) is a competing technology/business and a regulatory environment that allows that competition instead of squashing it. How likely is that? Too bad there's no easy formulas there.....
PJRC: Electronic Projects, 8051 Microcontroller Tools
Speaking as one of those in the UK sitting pretty much on the wrong side of the limit of the 5.5km restriction we have on British Telecom's ADSL implementation, the range increase may be more promising.
I'll hit the maths a bit -
Asssuming all the lines radiate directly out of the exchange so you can assume the range limit proscribes a circle with the exchange at the center (you can tell I'm a physicist can't you?)
The range increase talked about in the UK is 5.5km -> 6km of cable length. Now compare the areas of these 2 circles.
5.5 x 5.5 x 3.14 = 95 km squared (approx)
6.0 x 6.0 x 3.14 = 113 km squared (approx)
So this gives an extra 18 km squared coverage. If we assume one household per 100 metres squared (not unreasonable in the UK) then this bring 1800 homes in range of broadband.
Of course in the real world things will vary, but I've seen figures from BT suggesting 6km will bring 97% coverage of the population.
The irony for me is I live 30 miles from London, 4 miles from the end of the runway of one of our major airports, 3 miles from one of the major motorways and yet my broadband options are the same as someone on a remote island, no ADSL, no cable, just my trusty 56k jalopy...