Terabit Speeds - Net Speed Ain't Seen Nothin' Yet (Bring it on baby!)greenspun.com : LUSENET : Grassroots Information Coordination Center (GICC) : One Thread
WOO HOO! Bring it on!!!! _________________________________
Net Speed Ain't Seen Nothin' Yet
by Leander Kahney
3:00 a.m. Mar. 21, 2000 PST
Scientists at leading research labs are starting to push the data-transmission capabilities of fiber-optic cable into the realm of the mind-boggling.
Setting a new record, researchers at Lucent's Bell Labs have for the first time managed to push an astonishing 3.28 terabits per second of data over a long stretch of fiber-optic cable.
A terabit -- thats a trillion bits -- is roughly equal to all of the daily traffic on the Internet for the entire world. The Lucent fiber could transmit three times the daily global Internet traffic every second.
However, experts say the Bell Labs breakthrough is just the beginning.
In a matter of years, the fiber-optic cable being laid today by telecoms across the globe could be transmitting data at a rate of tens of thousands of terabits per second.
At these speeds, the entire written works of mankind could be beamed across the globe at the speed of light in just a few seconds.
Optical fiber is made from a silica fiber stretched thinner than human hair. Information is beamed across it by lasers operating in the near-infrared range of the light spectrum. More than 215 million kilometers of optical fiber has been laid across the globe, more than enough to stretch to the moon and back nearly 280 times.
The astonishing advances in bandwidth will largely be driven by two factors, said David Nagel, president of AT&T Labs: the speed of lasers used to encode the data, and the number of lasers operating at different wavelengths that can be carried by a single fiber.
Right now, the number of pulses generated by a single laser roughly follows Moore's law: The capacity doubles every 18 months.
Nagel said that scientists are developing terabit lasers, which would be capable of handling all of AT&T's daily telephone traffic -- more than 3 million calls -- plus all the data traffic, all on a single laser.
Meanwhile, the number of wavelengths, or colors, a single fiber can simultaneously carry is doubling every year. At the moment, optical networks carry 40 wavelengths per fiber, Nagel said. Eighty-wavelength systems are already available, and 160 wavelength systems will be introduced next year. Nagel said researchers are already experimenting with 1,000 wavelength systems.
"It's an astounding amount of capacity," Nagel said.
Kerry Vahala, a professor of applied physics at the California Institute of Technology, said today's optical networks are theoretically capable of being upgraded to transmit several thousand terabits of data per second.
By Vahala's calculations, the Bell Labs terabit breakthrough represents less than half a percent of the potential capacity of today's optical networks.
Surprisingly, the know-how for pushing optical networks to these dizzying heights was developed 20 years ago, Vahala said.
"Look at the commercial deployment of research technologies historically," he said. "It just doesn't happen until there's a huge demand. And that came from the Internet."
But he noted that the global networks currently being created by companies like AT&T, Global Crossing, Nortel, QWest, Alcatel, and hundreds of others probably only have enough potential bandwidth to handle the traffic for the next 10 years.
"They want to put something in this year that won't be changed for at least 10 years," he said.
And after that?
"It's just too far out to tell," said Vahala, laughing.
At Bell Labs, scientists set the new record by transmitting the 3.28 terabits of data over 300 kilometers, or 180 miles, of Lucent's TrueWave optical fiber. TrueWave is a common fiber in Lucent's optical networks, a spokesperson said, adding that the results should be reproducable at any distance.
The researchers transmitted 40 gigabits -- that's billion of bits -- per second, split between 82 wavelengths. The results were presented at last week's Optical Fiber Communications conference.
"These are interesting milestones but they don't have a lot to do with today's commercial market," said Tom Valovic, an analyst with market research firm International Data Corp. "The time it takes to get to commercial market is often quite a stretch."
-- Jen Bunker (firstname.lastname@example.org), March 21, 2000