Lucent Technologies' Bell Labs scientists set new fiber optic transmission record


Bell Labs scientists transmit 64 channels of data at 40 gigabits per second per channel over 4000 kilometers (2500 miles)

ANAHEIM, Calif., and MURRAY HILL, N.J. - Scientists from Bell Labs, the research and development arm of Lucent Technologies (NYSE: LU), have doubled the distance record for high-bandwidth, ultra long-distance transmission by sending 2.56 terabits (trillion bits) of information per second over a distance of 4000 kilometers (2500 miles), roughly the distance between Orlando, Fla., and San Diego. The previous transmission record was 1.60 terabits of information per second over 2000 kilometers (1250 miles).

"This breakthrough will ultimately enable lower capital and operational costs for our customers," said Tim Sullivan, president of Lucent's optical networking group.

A technical paper detailing the achievement is being presented today at the post-deadline session of the Optical Fiber Communications (OFC) conference in Anaheim, Calif.

The ultra long-haul all-optical transmission record was achieved using a 64-channel dense wavelength division multiplexing (DWDM) system, where each channel carried information at 40 gigabits per second. (Sending a gigabit of information per second is equivalent to transmitting the information content of approximately 1,000 novels every second; sending 40 gigabits per second over 64 channels is equivalent to transmitting the information content of 2,560,000 novels.) The DWDM technique, invented at Bell Labs, makes it possible to send multiple streams of information down the same optical fiber.

The fiber optics spans used in the Bell Labs experiment were 100 kilometers (62.5 miles) in length, typical of terrestrial networks used by service providers today. The previous distance record for a 40 gigabits per second transmission experiment over 100-kilometer fiber spans was exactly half of the 4000 kilometers (2500 miles) distance record that the Bell Labs team achieved, and the team used 64 channels whereas the previous experiment had used 40 channels.

"With this new result we have once again demonstrated Bell Labs' pioneering leadership in optical transmission systems," said Rod Alferness, senior vice president of optical networking research at Bell Labs.

The transmission breakthrough was made possible using the differential phase shift keying (DPSK) method, a new coding scheme for high-capacity communications developed at Bell Labs. When coupled with other leading-edge Bell Labs technologies - such as extended L-band amplifiers, Raman amplifiers, forward error correction and optimal dispersion compensation - DPSK allowed the research team to achieve error-free transmission over 4,000 kilometers (2500 miles) for all 64 channels, each of which had a signal of 40 gigabits per second.

This long-distance transmission achievement comes on the heels of Lucent's introduction of its LambdaXtreme Transport optical networking system, which can transmit enormous amounts of information across continents at one of the lowest costs per bit per kilometer in its class. LambdaXtreme Transport is being field tested by Deutsche Telekom and is generally available to customers. Developed by Bell Labs, it is the first system to power a 40 gigabits per second signal up to 1,000 kilometers (625 miles).

"It shows that close collaboration between Bell Labs and the business unit delivers real value to service providers," Sullivan said.

With approximately 16,000 employees in 16 countries, Bell Labs is the leading source of new communications technologies. Bell Labs has generated more than 28,000 patents since 1925 and has played a pivotal role in inventing or perfecting key communications technologies, including transistors, digital networking and signal processing, lasers and fiber-optic communications systems, communications satellites, cellular telephony, electronic switching of calls, touch-tone dialing, and modems. Bell Labs scientists have received six Nobel Prizes in Physics, nine U.S. Medals of Science and six U.S. Medals of Technology. For more information about Bell Labs, visit its Web site at

Lucent Technologies headquartered in Murray Hill, N.J., USA, designs and delivers networks for the world's largest communications service providers. Backed by Bell Labs research and development, Lucent relies on its strengths in mobility, optical, data and voice networking technologies as well as software and services to develop next-generation networks. The company's systems, services and software are designed to help customers quickly deploy and better manage their networks and create new, revenue-generating services that help businesses and consumers. For more information on Lucent Technologies, visit its Web site at

For more information, reporters may contact:

Saswato Das
Lucent Technologies
(908) 582-4824

Rich Teplitsky
Lucent Technologies
(908) 582-5700

Wendy Zajack
Lucent Technologies
(908) 582-8190