Ian AUSTENMAY 27,1999 AT&T, which was American online and parts after the latest traffic accident, also, there is widespread concern about the constant
The spiral of internet use will create a network deadlock in the United States.
This has not happened except for some glitches.
However, the rescue of communication networks comes from theoretical physics and high-tech fields.
It's not electrons, it's horizontal optics.
Through an alchemy called reuse-
Its more troublesome name is dense wavelength division multiplexing. -
Telephone companies and Internet service providers can quickly increase capacity while reducing costs.
The secret ingredients are light.
The use of light photons to achieve this goal, a field called Photon Science, may eventually change the way computers operate and increase their capacity.
"Without fiber and this method of increasing capacity, there would be no world wide web . "
Erich Ippen, professor of electrical engineering, computer science and physics at MIT.
"It just makes everything.
The revolution in photon technology is coming.
The concept behind reuse is both old and relatively simple-
It is based on a new method of using fiber optic cables.
The first fiber optic system is the backbone of the Internet and the long-distance telephone network, sending only one laser stream
Generate light pulses on each thin line of fiberglass.
Each cable usually carries between 96 and 150 strands.
With such a large capacity, the only problem with phone companies at the beginning was to populate their systems.
But the popularity of the Internet quickly dispelled the concerns and allowed the companies to look for more capacity.
In order to find this ability, the engineers turned
From the known concepts of broadcast and television broadcasting technology, single-strand fiber can carry many different information flows or channels at the same time.
The trick is that each data stream must be sent at a different frequency--
In the case of laser, this means color.
Advertising of fiber optic systems, hundreds of different information streams can be transmitted simultaneously along each chain in the cable.
Unlike subatomic particle electrons that make everything electronic, photons are the energy packets of light.
"You can take a closet and fill it with electrons because they are particles," said Kathy selag, vice president of marketing at Lucent technology optical network group.
"But if you pump the photon into the same closet, it will never be filled with light.
There are no physical restrictions.
In addition to Lucent, the Nortel Network, Pirelli cables and systems, and Ciena have also made photon multiplexing systems.
However, like many elegant theories, multiplexing is a strategy that has to overcome an important problem in order to actually apply: When photons cross along them
They began to travel scattered and slowly.
Therefore, it is necessary to enlarge the signal in the fiber optic line.
Earlier fiber optic systems used a complex patchwork in which signals were converted from light to electricity, enhanced electronically, and then into light.
This process is embarrassing, reducing the maximum speed of the system.
Electronic amplification also makes it too expensive and complex to run multiple frequencies or channels.
Each channel in a single fiber cable strand needs its own electronic amplifier every 25 miles or so, and the cost per amplifier is about $75,000.
Since state-of-the-art cables have more than 100 channels per share, setting up more fiber cables is still a cheaper way to increase network capacity.
The breakthrough in technology, the optical amplifier, has changed all this.
In 1990s, it was about the time when the Internet began to demand the Internet.
The optical amplifier uses a newly developed laser to excite photons as they pass through.
Not only are they cleaner in operation, but a single optical amplifier can stimulate many different channels at the same time, and the resulting signal travels further than the electronically amplified signal.
Suddenly, changing the way the signal is sent is cheaper than laying more fiber optic cables.
For AT&T, which installed the first photon multiplexing system in 1995, the optical amplifier is the answer to prayer.
AT&T expects its network demand to grow 500% over the next five years-
Almost all growth comes from internet traffic.
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"Thankfully, the technology is developing rapidly . "
George Garriss, planning manager for AT&T's transportation network division.
"It would be a bad choice.
"Reuse not only allows the network to expand without adding an inch of new optical cable, but also saves money, further reducing the price of long-distance calls and internet connections. Mrs.
Lucent's Szelag estimates that the cost of increasing capacity using multiplexing is about 1-
Fifth, the cost of laying more cables.
The first system purchased by AT&T runs eight optical channels per string-
All these are invisible to the human eye.
The state-of-the-art system currently sold by Lucent offers 80 channels per share of fiber, allowing fiber per share to carry 400 billion bits of information per second.
So each chain is able to move 5 million phones, or 600 CD-content at the same time
According to Lucent, there is a ROM every second.
Everything is impressive though, madam.
Szelag said that the development phase of the optical network is roughly the same as the electronic products of the first HP company.
The HP calculator came out.
"Our job now is to make photons as important as the 20 th electron before the 21st century," she said . ".
There is also a big problem to overcome in the photon industry.
Reuse is now only useful in extremely high Cases
Because it does not have a system for effectively exchanging or routing data and phone calls, capacity lines travel long distances.
In the change of the old amplifier problem, all of this occurs in a dedicated computer after the photon is converted into an electron. Some small ones.
Scale photon switch developed using "micro"
Mirror controlled by electronic
It has been shown that work based on computer and optical exchange is carried out within the laboratory.
But the long term of this industry
The word dream is to create networks that can become all-optical networks.
Recently, Trellis Photonics, an Israeli company, began developing a crystal-based optical switch.
Optron Systems, a NASA and Massachusetts company, is also working on similar technologies.
If such research can successfully implement optical switches and routers, it will be an important step towards the optical computer, which can theoretically run at a very fast speed.
Many problems must be overcome to get there.
One of the most important issues is that there is no photon storage device to provide the functionality of a hard disk or floppy disk.
If optical computing turns out to be feasible, then it will be a huge change in technology so that some people may even use some novel descriptions to understand its final form far beyondMs.
Szelag says the ethereal nature of photons may mean a strange computer, which does lead to the idea of "a computer without anything.
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A version of this article was printed on page G00013 of the National edition on May 27, 1999, with the title: What is next;
Compress the data of 80 "cups" into 1 cup.