Paris, September 28, 2009 – Alcatel-Lucent today announced that
scientists in Bell Labs, the company’s research arm, have set a new
optical transmission record of more than 100 Petabits per second.kilometer
(equivalent to 100 million Gigabits per second.kilometer). This transmission
experiment involved sending the equivalent of 400 DVDs per second over 7,000
kilometers, roughly the distance between Paris and Chicago. This is the highest
capacity ever achieved over a transoceanic distance and represents an increase
that exceeds that of today’s most advanced commercial undersea cables by
a factor of ten. To achieve these record-breaking results the Bell Labs
researchers made innovative use of new detection techniques and harnessed a
diverse array of technologies in modulation, transmission, and signal
processing
High speed optical transmission is a key component of Alcatel-Lucent’s
High Leverage Network™ architecture, key elements of which have already
been selected by leading service providers.
To achieve these record-breaking results researchers from the Bell Labs
facility in Villarceaux, France used 155 lasers, each operating at a different
frequency and carrying 100 Gigabits of data per second, to dramatically enhance
the performance of standard Wavelength Division Multiplexing (WDM) technology.
“There is no question that this record breaking transmission is a
milestone in achieving the network capacity and speeds and a key step forward
in satisfying the ongoing explosion in demand,” said Gee Rittenhouse,
head of Bell Labs Research. “This is a prime example of Bell Labs
preeminent research and demonstrates the ability of our researchers to solve
complex problems,” he explained.
The record-breaking figure was derived by multiplying the number of lasers
by their 100 Gigabit per second transmission rate and then multiplying the
aggregate 15.5 Terabit per second result by the 7000 kilometer distance
achieved. The combination of speed and distance expressed in bit per second.kilometers
is a standard measure for high speed optical transmission.
The transmissions were accomplished over a network whose repeaters, devices
used to sustain optical signal strength over long distances, were spaced 90
kilometers apart. This spacing distance is 20% greater than that commonly
maintained in such networks. The challenge of maintaining transmission over
these distances was significantly heightened in these experiments because of
the noise –perturbation of signals– that is introduced as
transmission speeds increase.
The researchers also increased capacity by interfacing advanced digital
signal processors with coherent detection, a new technology that makes it
possible to acquire details for a greater number of properties of light than
the direct detection method commonly applied in today’s systems. Using
this technique the researchers were able to effectively increase capacity by
increasing the number of light sources introduced into a single fiber yet still
separate the light into its constituent colors when it reached its destination.
Details of the breakthrough were presented in a research paper that was
reviewed in an exclusive and highly-competitive post deadline session of ECOC
2009, a prestigious European optical communications conference.
This transmission record is just the latest in a long series of Bell Labs
optical networking breakthroughs that have become market-changing solutions and
generated substantial growth opportunities for Alcatel-Lucent: the invention of
Dense Wave Division Multiplexing (DWDM), introduction of non-zero dispersion
fiber, 100 Gigabit Ethernet field trials and Differential Phase-Shift Keying
(DPSK) at 40 Gigabits per second, the most widely used in 40 Gigabit per second
systems worldwide.