Vendors closing in on 1Gbps using DSL
- 26 October, 2010 23:43
- Comments 5
DSL vendors are using a variety of methods such as bonding several copper lines, creating virtual ones and using advanced noise cancellation to increase broadband over copper to several hundred megabits per second.
At the Broadband World Forum in Paris, Nokia Siemens Networks became the latest vendor to brag about its copper prowess. It can now transmit speeds of up to 825M bps over a distance of 400 meters, it said on Monday.
However, the company isn't alone in wanting to tell about the kind of speeds next-generation DSL (Digital Subscriber Line) systems can achieve. Last week, Huawei said it can transmit 700M bps over the same distance. Today, Alcatel-Lucent said it has achieved 910M bps in its latest round of tests over 400 meters, according to a spokesman.
To boost DSL to those kinds of speeds, the vendors are using a number of technologies. One way is to send traffic using VDSL2 (Very high bit-rate Digital Subscriber Line) over several copper pairs at the same time, compared to traditional DSL which only uses one copper pair. This method then uses a technology -- called DSL Phantom Mode by Alcatel-Lucent and Phantom DSL by Nokia Siemens -- that can create a third virtual copper pair that sends data over a combination of two physical pairs.
However, the use of these technologies also creates crosstalk, a form of noise that degrades the signal quality and decreases the bandwidth. To counteract that, vendors are using a noise canceling technology called vectoring. It works the same way as noise-canceling headphones, continuously analyzing the noise conditions on the copper cables, and then creates a new signal to cancel it out, according to Alcatel-Lucent.
To get really high speeds vendors are using four copper pairs, which will not be readily available among broadband operators. A more realistic scenario is using two copper pairs, which can still boost the bandwidth to 390M bps over 400 meters, according to the latest tests done by Alcatel-Lucent. In general, vectoring can bring significant advantages at distances up to 1,000 meters, Alcatel-Lucen said.
ZTE is taking an even more cautious approach, and said on Friday it can reach 100M bps using VDSL2, vectoring and one copper pair over 300 meters.
Products are now entering field trials and operators will be able to start using them in commercial services during next year.
Copper is still the most common way of carrying fixed broadband, with a share of about 65 percent, compared to 20 percent for cable and 12 percent for fiber, according to market research company Point Topic.
Fiber all the way to the home is the ideal long-term solution for fast broadband, but the new technologies will help operators offer faster speeds using copper as fiber coverage is expanded over the coming decades, vendors agree.
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Comments
Copper faster and greener
There you go, we can have it all for next to nothing.
Vendors agree.
And even if the copper is green. ANd its not, its ok for most for the next 40 years or more, far longer life span than the fibre or the massive cost of duplication our entire communications infrastructure.
Conroy's con job revealed, no asked us what we wanted or gave us a choice.
These global innovations in using existing access and alternative and advances in technology will all be denied to Australia/
Complete Moron
Haha! Go to hell Conroy! Your veil of lies has finally been stripped.
All we have to do now is double the amount of copper capacity to every home in Australia, and move every house within 1km from the exchange. I guess we would have to move the copper out of the ground and into a lab where they get these kinds of results; but that's not a big deal because it proves the NBN IS A SCAM!!!!
I think the main point of this article is I can apply my completely uneducated reasoning to this article and use it to bash something else I don't understand! By the way, turns out Global Warming is actually a farce, I was outside this morning and it was colder than usual! Explain that, dummy scientists!
actually a tax paying anti moron
@2 this one doesnt pay tax or read the papers. He is a call centre worker that thinks somehow he is correct and that when respected technology vendors state that 100mbs over normal coppper wire is quite within expectations in the next 5 years in the field, as they did, that he somehow knows better.
The existing network doesnt need to be doubled or houses moved or anything.
The NBN is a scam built on lies from day one that sucked in boofheads like @2 as evalangilists and NBN fan boy trolls. Well didnt this troll and others do a crap job of convincing the public. takeup <10%, no one wants it, sustained and increasing discontent - and now even THE VENDORS say this NBN is crap and isnt needed.
And yep, the NBN contributes to Global Warming, the largest wastage ever of embedded and then non productive material and energy so far in Australia with zero result. Just take 23m toxic batteries, all sucking off the grid. The NBN will warm up your day for you little man even if you cant make a useful digital or taxation contribution and just continue to bludge off the rest of us.
USA NBN CTO comments
Blair Levin was the lead author of the US Government's version of the NBN, the National Broadband Plan, which has faced similar controversies and he says its not speeds, feeds, fibre but composite, mixed, existing copper as per this article and especially mobile wireless. (ARNNET article yesterday).
He backs it up that no-one has achieved any 'productivity' in NBN's that are like the current Australia design.
He says the Australia NBN design is wrong and will prevent innovation and technology futures.
@2 complete moron - yep you are and no irony intended..
HazTechDad
@3: How do you think your current telephone is powered in a blackout? By miracle power? The only difference with the NBN is that instead of there being a bank of massive lead-acid batteries in the exchange, there will be a little one in each house. Telstra currently have to replace them, and pay to keep them charged. All part of the cost you pay them for your 'line rental'. You may also note that Australian's dispose of twice as many lead-acid car batteries as they will NBN batteries, and they are considerably larger.
@1, 3, 4:
Look at the distances here people...300metres, 400metres!!! Practical ADSL speeds have been stuck at <24Mbps for 7 years now.
How many Australian homes do you think are within ~300 metres (in wire) of an exchange? Allowing for the wire used to route through the exchange, down into the ducts (or up the poles) and back into the house, then to the modem, we are talking about premises that are within maybe 200 metres of a telephone exchange, who may be able to achieve the experimental speeds quoted above.
These DSL upgrades are still band-aid solutions stretching the last few drops out of an old, obsolete technology. By contrast, 1Gbps is just the starting point for fibre. Existing technology sends over 100Gbps down a single fibre strand, so our rollout of a "1Gbps" NBN is just the start of futureproofing our data needs. In 50 years our NBN can likely be ramped up to 1Tbps and beyond, while copper will have gone the way of the dodo.
But, for all Australians who:
a) Live within 200-300m of a telephone exchange; AND
b) Already have 2 pairs of copper to their premises; AND
c) The copper is in good condition
....the above improvements in DSL tech would be great. The question is what portion of Australian premises meet the above 3 conditions? Maybe 10%? What about the rest of us?
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