MITSUBISHI ELECTRIC CORPORATIONPUBLIC RELATIONS DIVISION
7-3, Marunouchi 2-chome, Chiyoda-ku, Tokyo, 100-8310 JapanFOR IMMEDIATE RELEASE

No. 2995

Customer Inquiries

Media Inquiries

Mitsubishi Electric Research Laboratories
www.MitsubishiElectric.com/ssl/contact/company/rd/form
www.merl.com/

Public Relations Division
Mitsubishi Electric Corporation
prd.gnews@nk.MitsubishiElectric.co.jp
www.MitsubishiElectric.com/news/

Mitsubishi Electric Develops 1Tb/s Multi-subcarrier Optical TransceiverTechnology
Realizes world-leading data rate using existing optical fiber network
TOKYO, February 15, 2016 – Mitsubishi Electric Corporation (TOKYO: 6503) announced today that it
has developed a multi-subcarrier optical transceiver technology that significantly increases the data rate of
terrestrial fiber optic communication. A single receiver was used to achieve a data rate of one Terabit persecond (1Tb/s), a 10-fold improvement over current mainstream commercial transceivers, which operate atup to 100 Gigabits per second (Gb/s) per optical receiver. This technology is expected to contribute to thedevelopment of next-generation networks that can use existing optical fibers to smoothly deliver
high-resolution videos and other data-heavy content to a larger number of users.

In optical communication, signals are carried on light waves known as carriers. Due to the limitation ofsignal bandwidth that can be generated without significant distortion, the throughput of a single carrier isalso limited. Mitsubishi Electric achieved the 1Tb/s transmission rate with existing optical fibers by using a
multi-subcarrier technology that transmits 11 light waves (subcarriers) simultaneously in a single channel by
1/2

using an optical comb, a device that creates a series of discrete, synchronized optical waves equally anddensely spaced in the channel. While conventional methods would require 11 receivers for the same numberof subcarriers, this new technology only requires a single receiver due to the use of densely spaced,synchronized subcarriers in a single channel and novel multi-subcarrier signal processing algorithms. No
major changes are required to the existing optical network infrastructure, keeping the cost of deploying thisnew technology quite low.

Usually, when using subcarriers for optical communication, each subcarrier undergoes different signal
distortions, which results in damaged data like video distortion on the receiving end. To avoid this problem,
Mitsubishi Electric used pilot signals to accurately realign the subcarriers at the receiver. Known pilot
symbols are periodically inserted into the transmitted signal, which serves as a landmark for correctorientation of all subcarriers and prevents data damage.

Due to the expansion of the Internet and smartphones, communication traffic is dramatically increasing.
Meanwhile, revenue is becoming decoupled from traffic volume as OTT (Over The Top) applications
provide various services free of charge. Communications companies need to provide high capacity as well as
low cost, so it is important to develop technologies that improve transmission capacity on the existing
optical-fiber network.

This technology has enabled an experimental demonstration of 1Tb/s net data rate transmission using asingle optical receiver. The experiment also achieved a spectral efficiency of 9.2b/s/Hz, which as of January
2016, was the highest in the world in a 1Tb/s transmission using a single optical receiver. In this work,
Mitsubishi Electric collaborated with the Optical Networks Group at University College London, who jointly
lead UNLOC, a large UK research project to unlock the capacity of optical communications, with a team at
Aston University.

Patents
The technology announced in this release has two patents pending in the US.
###About Mitsubishi Electric Corporation
With over 90 years of experience in providing reliable, high-quality products, Mitsubishi Electric
Corporation (TOKYO: 6503) is a recognized world leader in the manufacture, marketing and sales ofelectrical and electronic equipment used in information processing and communications, space development
and satellite communications, consumer electronics, industrial technology, energy, transportation andbuilding equipment. Embracing the spirit of its corporate statement, Changes for the Better, and itsenvironmental statement, Eco Changes, Mitsubishi Electric endeavors to be a global, leading green company,enriching society with technology. The company recorded consolidated group sales of 4,323.0 billion yen(US$ 36.0 billion*) in the fiscal year ended March 31, 2015. For more information visit:
http://www.MitsubishiElectric.com*At an exchange rate of 120 yen to the US dollar, the rate given by the Tokyo Foreign Exchange Market on
March 31, 2015

2/2