Copper wire as fast as fiber?

bealtine

10/10/2006 4:22:03 PM, by Nate Anderson

http://arstechnica.com/news.ars/post/20061010-7952.html

Imagine that you're the guy who has to deliver the bad news. You straighten your tie, clear your throat, and jangle your keys as you step into your boss's office. She does not look like an executive who has gone to the sorts of conferences where managers are reminded not to shoot the messenger. It is, in fact, quite possible to imagine her stashing a Glock just out of sight in a desk drawer. Come to think of it, it's been months since you've seen Jenkins, the last guy to deliver bad news. "Boss," you begin, "about that $18 billion we just spent? Well, turns out it wasn't strictly necessary..."

It's a conversation that could be playing out at telcos like Verizon in the next few years if a new consortium of hardware vendors and phone companies has its way. The group is led by ECI Telecom and includes members like Spanish telephone giant Telefonica, but it's based in Israel and funded in part with a grant from the Israeli government.

The group's goal is audacious: achieve fiber optic speeds over copper wire. If they succeed, Verizon's $18 billion decision to run fiber all the way into consumers' homes might be a costly one for them and other companies around the world that have jumped on the fiber optic bandwagon.

The group hopes that the answer will be found in the use of Dynamic Spectrum Management (DSM) to boost DSL speeds. "The main obstacle for the advancement of DSL technology is the interference ("crosstalk") generated from different DSL lines that share the same telephone cable binder," said Professor John Cioffi, Professor of Engineering at Stanford University, a pioneer of DSM research. "DSM is a promising technology for the future evolution of broadband access networks using existing copper infrastructure."

To avoid interference, current DSL implementations use static spectrum management that is built for a "worst-case" scenario. Most actual phone lines would allow for far better performance, and DSM technology will allow each DSL connection to be regulated in real time by the hardware based on measured crosstalk and on current data needs of each customer. The end result could be DSL connections that top out at 100Mbps or more.
More bandwidth than fiber?

One of Dr. Cioffi's presentations of DSM contains a slide that argues that copper actually has more available bandwidth than fiber; it just needs to be better used. He points out that a bundle of 50 Cat 3 twisted-pair wires (the kind that might be used in the last segment of the phone network) has 10Gbps of available bandwidth to distribute to the fifty homes at the end of those wires. By contrast, fiber to the home has only 2.5Gbps to distribute to its homes.

"DSM is the next step in the evolution of telco's access infrastructure. It will allow telcos to provide high-bandwidth services cost-effectively by leveraging FTTC (fiber-to-the-curb) topologies rather than replacing all copper wires with fiber-optics until the subscriber premises (fiber-to-the-home)," said Zvika Weinshtock, VP of Marketing for ECI's Broadband Access Division.

It's not hard to see why this technology would interest telcos. Many have moved slowly on FTTH deployments over cost concerns. Others, like Qwest, have decided to remain on the sidelines. DSM, should it provide good real-world results, could keep the existing copper infrastructure competitive for many more years, and could give DSL users massive speed boosts, something welcome to power users who might cast a lustful eye on faster FiOS or cable modem connections.

While Verizon has made a big bet on FTTH, don't call the money wasted just yet. The commercialization of DSM is just beginning, and real-world results may never jibe with laboratory experiments. For the forseeable future, FTTH still offers the fastest available speeds.

watty

Also just like you can change the plant on copper to "go faster", you can change the plant on fibre to get 200Gbps or more instead of 2.5Gbps. Most fibre runs 2.5Gbps because the plant for higer speed is more expenive and mostly the 2.5Gbps is fast enough. I'd bet like NEC's VDSL the higher speeds are only on good TP for short distance. Good to get from the cabinet to the house. We really don't need fibre to the home, just to the nearest cabnet.

bk

The problem with this is that in order to get the higher speeds you need good, high quality clean copper cable. Does anyone seriously think that the Eircom network is anything like this.

So in order to take advantage of this, you would need to replace a lot of cable and sure if you are doing that, you might as well use fibre as the truck roll and road digging makes up the majority of the expense, not the cable used.

In fact if you are laying new cable, the best thing to do is simply lay cat3, coax and fibre together.

bealtine

bk wrote:

In fact if you are laying new cable, the best thing to do is simply lay cat3, coax and fibre together.

or just lay fibre/triax

crawler

What utter utter rubblish.

One could easily run 16 X 2.5Gbps CWDM channels on a SINGLE fibre (not a pair) to any point needed. Have a look at (google) Transmode for proof.

The day that the capacity of twisted pair copper can exceed that of fibre, I will eat my hat.

I love when people try to bend the laws of physics and then magically it does not work.

The point on DSM is valid and indeed correct and personally I feel a lot will be done in finding a better way to improve DSL speeds over time. But this arguement also totally ignores the fact that improvements are being made at the photonic layer on fibre all the time with things such as iridium doped amplifiers and tuneable lazers.

This is another example of vendor led hype - Betamax or WAP anyone?

Makes me sad....

Urban Weigl

Betamax was actually better, but the porn industry chose VHS. As far as WAP, well, all the Irish mobile providers still swear by it, O2 being the exception by offering i-mode.

But back on topic, they're not really talking about exceeding the speeds that fibre can offer. They're simply talking about squeezing a few more years out of legacy copper infrastructure. If they can provide near-100Mbps speeds, that means telcos can offer new services (think HDTV and others) without upgrading everyone to fibre overnight. If it works in the real world.

bealtine

crawler wrote:

The point on DSM is valid and indeed correct and personally I feel a lot with be done in finding a better way to improve DSL speeds over time.

Well yes, I've heard of fibre doing up to 14Tbs. I dont think copper will never get to those speeds:)

But its a bit of flippant "reporting"...if they can get speeds up to 100mbs over copper would you like salt or pepper with the hat?<grin>

crawler

bealtine wrote:

Well yes, I've heard of fibre doing up to 14Tbs. I dont think copper will never get to those speeds:)

But its a bit of flippant "reporting"...if they can get speeds up to 100mbs over copper would you like salt or pepper with the hat?<grin>

Ah I was being a bit unfair too - just to provoke a reaction!

VDSL2 will do 100Mbps TODAY (at a distance of about 4 inches from CO!!) so I guess I better break out the salt and pepper then!

Foxwood

bealtine wrote:

While Verizon has made a big bet on FTTH, don't call the money wasted just yet.

Verizon operate in a strongly reguated environment, and have to unbundle the copper local loop at a price set by the regulator, because it is part of the legacy infrastructure built up when Verizon was part of Ma Bell, which had a legal monopoly. One of the drivers for Verizon to roll out fibre is that it doesn't have to share that fibre with any 3rd parties.

Verizon isn't just rolling out Fibre - it's actively pulling the copper out at the same time.

If anything, the possibility of competitors using Verizons copper to deliver competing triple-play services might actually lead to an acceleration of Verizons fibre roll out.

crawler

Which is why Verizon want to undo unbundling

http://www.lightreading.com/document.asp?doc_id=103202

And so the cycle continues.....

watty

There's been gigabit copper a long while, but not on Irish Wires. Fibres are really waveguides. What ever you figure out to put on a wire you can replicate it x 10,000 on a fibre eventually.

seamus

There'll never be a development for copper that will make anyone think that money spent on fibre is a waste. Any development that eeks out a few more Mbps from a copper line can only help delay any move to fibre. For WAN and LAN backbone infrastructure, fibre is the way to go. Copper will always be useful for short range (< 50m) comms, because it's so cheap and the cables are easy to make/repair yourself.

jimmycrackcorm

What! Copper faster than the speed of light?

Personally I await the advent of time travel when google will send you the answers before you post the question...