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Copper Wire As Fast As Fiber?
Krishna Dagli writes to tell us that a new consortium of hardware vendors and phone companies have banded together in order to try for fiber optic speeds over copper wiring. From the article: "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."
But when will it hit my doorstep at a reasonable rate?
All this talk of speedy internet access is great, but I'm still not seeing much benefit when it comes to what my ISP offers.
Copper Wire as Fast as Fiber? What a misleading topic. How about 'Copper Outside Plant can rival current FTTH speeds,' as this is much less inflammatory and more on target with what is intended to be said. With such a general topic there's no telling what the story is actually about, and in this case, it's not any of the following:
-Copper Outside Plant transmits data at OC-192 speeds
-Lab makes Copper transmit OC-48 speeds
-Copper Wire discovered to have same frequency versatility of fiber
-Police Cables allow bacon to move at speed of light
Sheesh.
love and peace
-cheez
it is hard enough getting ISP's (in this case those dirty theiving telco's) to pony up the actual bandwith advertised on a simple 1.5Mbps DSL line. I might be able to get 100Mbps to the DSL suboffice but I seriously doubt that ISP's would be willing to pay for the connection further down the line to actually provide that kind of speed to anything outside their local network. ISP's tend to oversell bandwith and hope for the best.
No. They're using hardware to monitor when the conditions are worst-case. It's obviously better than assuming the conditions are always as bad as they could possibly be.
ResidntGeek
So, in other words there's a technology to make existing infrastructure MUCH more efficient. Don't hold your breath waiting for it. DSL is owned by whom? The monopoly telephone companies, and with the recent court rulings that say they don't HAVE to sublease it is not likely there will be 1:1 competition in the near future. My guess is that the phone companies will see this as an excuse to raise prices, due to perceived value*, rather than to provide improved performance that competes with cable at a similar, or lower price.
*Just as CDs cost less to manufacture than cassette tapes, but until recently sold for more $$, such as it will be with "extreme DSL" (or whatever they call this service).
The article title implies that a copper wire can have more bandwidth than a fiber. Read on:
See the switch in argument? From "copper > fiber" in the title (and other locations within the article to boot) to "copper*50 > fiber*1". I'm sure if I bundle 10,000,000 twisted pairs then I can out-bandwidth a single fiber any day, but does that mean I should say copper is faster than fiber?
It's like titling my article "3.5 inch floppies hold more than a hard drive?" but then say if I combine 2 billion floppies in parallel then I get 3 TB of storage where as a single hard drive only holds 700 GB.
Apples and oranges.
That said, I think the article is trying to point out that the existing copper can be better utilized and achieve higher bandwidth than if a new, single fiber were trenched in its place. I see little controversy in this. But this does not mean "copper > fiber".
I have to admit that this is probably one of the most confusing and poorly written Ars article I've ever read.
:wq
Well, it's all depending on your sense of scale.
The propagation velocity of an electrical charge down a conductive wire is a significant fraction of the speed of light. In most cases, this might as well be the speed of light, because it's so much faster than anything else that we do, or work with. (The current doesn't actually flow at the speed of light, because not all the electrons are moving in a straight line down the wire. So even though the electrons are moving at the speed of light, the net velocity of the charge is some fraction thereof.) Something sticks in my mind about electricity usually propagating at around 0.3c, but I can't substantiate that.
However, light travels down a fiber optic cable at, unsurprisingly, the speed of light. This can be anywhere up to 3x faster than a signal moving down a conductive cable, depending on the properties of the fiber and the cable.
So while light is significantly faster than electricity, for all practical purposes today, they're both "really, really fast;" the limitations to data capacity arise for other reasons, mostly related to bandwidth, and not because of the time that the signal takes moving down the wire.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
I have a couple of concerns with the direction this article takes.
1. To say that any money spent on FTTH is money wasted due to the potential of this completely untested technology is really unfair to say the least. At this point we do not know if the new tech will even provide results. Also, there are many places that really do have terrible copper, especially in the consumer markets. Many old homes and apartments have copper that cannot even use current DSL, let alone attempting to use an even more intensive signal.
2. At the beginning of the article the person paints a picture of a guy going to his boss to tell them that we may have made a mistake in going with this FTTH idea. This is about the dumbest thing this person could do because a) The decision is made and cannot be undone and b) if the boss is not putting pressure on you do not bring up things that you cannot do anything about which will get your ass in trouble. It is never a good idea.
I can see where the person is coming from. We should be honest and come forth and say we should do this, even though we initially thought we should of done and did do that. Unfortunately our corporate climate has never been overly friendly to brute honesty. The last thing you want to do is stand up in a loud voice admitting guilt to the problem. It is like saying, "Well I ment to get it done, but x, y, and z happened." Sorry but ment to and what actually happened are two entirely different problems. Now your SOL.
Brendan
You see, the internet is like a stream in the woods.
Water in the Amazon river and a stream may travel at the same speed, but the Amazon moves a heck of a lot more water in a given period of time than the stream. This difference is analogous to bandwidth. Electrical signals and light signals both travel at essentially the same speed (though I believe there is actually a small difference in the real world), but fiber can carry a lot more data than copper.
A physical limitation to any transmission medium is the propagation delay from one point to another. Sure, you may get the same unidirectional transfer rate with copper compared to wire (which I doubt considering the possible frequencies involved), but bi-directional communication will be hampered by the propagation delay, in which fiber obviously has the upper hand. There are other issues regarding the resistance of the medium, forcing you to add repeaters periodically, but I digress for now.
Note: electrical signals do *not* propagate at the speed of light through copper.
Even if the fiber that's being taken out to your curb can take 100Mb/s, if they don't think there's a market for it, they probably aren't buying the backhaul capacity to provide that level of service.
In other words, they might be able to get you hooked up at 100Mb/s, but you'd only be able to talk to your neighbors and other people on the local subnet at that speed.
This is a real problem for almost all broadband ISPs, because they're just not buying the capacity from their Tier 1 ISP that they should be, in order to offer even the speeds that they're advertising to people. "Real" internet connections -- and by that I mean ones to upper-tier ISPs with bandwidth and QoS and uptime guarantees -- are not cheap, and thus they get skimped on.
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
... here we can get 16 mbit dsl for ~60 euro together with a telefon flatrate. But it's of little use since your upload is 1 mbit. You can't really use your big pipe since most servers won't give out data that fast. And distributed networks which could saturate this pipe won't work because one is not able to feed back that fast and so you're stuck on 1-2 mbit down (e.g. bittorrent).
So it's great that they're testing new technologies but the real bottleneck isn't bandwith to the costumer but their ability to send data.
When I first got a cable connection, in late 1997, the modem was $300, the installation fee was $150 or so, and the monthly fee was $50. I had a static IP address and the only limitation on my bandwidth up and down was the local application or remote server's ability to feed the data into the 'net, so far as I could tell.
Then some of my neighbors starting getting a cable modem...
Now it's all different. But the interesting point is that the cable modem is about 1/3 the price, there is usually no installation fee, and the monthly fee is still $50, despite 10 years of inflation. DSL is typically even less. In other words, the main development in broadband over the past 10 years has been a fall in the real price and a lot more people using it. (I'd say, personally, it's also a bit more reliable -- in '97 the cable net connection would flake out for an hour or so every few days. Now it almost never does. But that's just one operator, YMMV.)
Had we wanted, instead, faster and better service at the same real price (e.g. $75/month in 2006 dollars), then maybe we'd have got that. But that is apparently not what our buying habits told the cable and DSL operators we wanted.
There's a lot of wire in the ground already.
And it doesn't matter how much it would cost to buy a pound of copper, if you already own it and already have installed it, it's cheaper to use it than to install fiber.
There's always money in making already installed cables work better to avoid installing new ones.
http://lkml.org/lkml/2005/8/20/95