Nec Corporation

Nec Laboratories America, Inc.

Nec C Orporation

Ryuji Aida

Philip N Ji

Ting Wang

Yoshihisa Inada

Eduardo Rodriguez

Fatih Yaman

Takanori Inoue

Takehiro Nakano

Hussam Batshon

Eduardo F Mateo Rodriguez

Yutaka Yano

Shinsuke Fujisawa

Kohei Nakamura

Kenichi Yoneyama

Yoshinari Takigawa

Ryu Kurahashi

Takigawa Yoshinari

In order to avoid the phenomenon of communication being impeded and signals transmitted by the plurality of slave devices overlapping, a communication system according to the present invention has the first master device transmits a first pulsed light to the first transmission path and receives a return light of the first pulsed light from the second transmission path; each of the slave devices modulates the first pulsed light, and outputs the modulated first pulsed light as the return light of the first pulsed light; and the width of the first pulsed light is narrower than double the shortest distance from among the transmission distance between the slave device outputting the return light and the transmission distance between the first master device and the slave device outputting the return light.

Communication system and method for controlling communication system

To provide an optical branch coupler which facilitates communizing the design of an optical transmission path, the optical branch coupler comprising: a first add drop unit for outputting a third optical signal to a first line in which a first optical signal received from the first line and a second optical signal inserted into the first line are multiplexed and outputting the first optical signal; and a second add drop unit for receiving the first optical signal, receiving a sixth optical signal from a second line different from the first line in which a fourth optical signal and a fifth optical signal dropped from the second line are wavelength multiplexed, demultiplexing the fourth and fifth optical signals, and outputting a seventh optical signal to the second line in which the fourth optical signal and the first optical signal transmitted by the first add drop unit are multiplexed.

Optical branching/coupling device and optical branching/coupling method

Aspects of the present disclosure describe systems, methods. and structures directed to an integrated 3-way branching unit switch module suitable for undersea application.

Integrated 3-way branching unit switch module having small footprint

An optical transmission apparatus outputs a main signal. An optical transmission apparatus superimposes a monitoring signal on an optical signal and outputs it. A submarine branching apparatus includes a return unit configured to return the monitoring signal received from the optical transmission apparatus and is configured to switch an output destination of the main signal received from the optical transmission apparatus to an optical transmission apparatus or the optical transmission apparatus. The optical transmission apparatus is configured to detect the monitoring signal returned from the return unit and notifies the optical transmission apparatus of a result of the detection. The optical transmission apparatus instructs the submarine branching apparatus to switch the output destination of the main signal in accordance with the notification.

Submarine optical communication system and submarine branching apparatus

Aspects of the present disclosure describe a three-way branching unit switch module having a small footprint suitable for application in an undersea application.

Three-way branching unit switch module having small footprint

An optical branching/coupling device includes: a first optical branching unit that splits first light with a first and a second wavelength, and outputs second light and third light; a wavelength selector that receives the second light, receives fourth light with a third wavelength, output fifth and sixth light, one of the fifth light and the sixth light including an optical signal of the first wavelength of the second light and including the fourth light, and the other including an optical signal of the second wavelength; a first light switch that receives the fifth light and the sixth light, output one of the fifth light and the sixth light as seventh light, and output the other as eighth light; and a second light switch that receives the third light, receives the eighth light, and outputs the third or the eighth light that have been input as ninth light.

In order to provide an optical transmission device capable of implementing the spectral control of WDM signals while taking into account optical component characteristics, an optical transmission device is provided with: a WSS; a wavelength monitor that outputs a signal expressing a first spectrum, which is the spectrum of the WSS optical output; an optical processing unit that subjects the WSS optical output to prescribed processing; a temperature monitor that outputs a signal indicating the temperature of an optical processing means; and a control unit that receives the input of the signal expressing the first spectrum and the signal indicating the temperature, and controls the transmission characteristics of the WSS on the basis of the first spectrum and the temperature.

Optical transmission device and optical transmission method

Aspects of the present disclosure describe systems, methods and structures including high-density submarine/undersea reconfigurable optical add/drop multiplexers (ROADM) having remote wavelength selective switch (WSS) redundancy.

High-density submarine ROADM unit with remote WSS redundancy

In order to provide a power supply path-switching device, a power supply path-switching system, and a power supply path-switching method with which it is possible to utilize to the maximum equipment in which a failure has not occurred without imparting a power supply function to a branch station side even when a failure has occurred in the power supply function of the trunk station side, a power supply path-switching device () is provided with a first switching means (), a second switching means (), a grounding means (), and a power consumption circuit () that operates by being supplied with the power supply. When a failure occurs in a first power supply line (), the power consumption circuit () grounds the first power supply line (), one end of the power consumption circuit () being connected to the grounding means () and a second power supply line () being connected to the other end of the power consumption circuit (). When a failure occurs in the second power supply line (), the power consumption circuit () grounds the second power supply line (), the first power supply line () being connected to one end of the power consumption circuit () and the other end of the power consumption circuit () being connected to a grounding means ().

Power supply path-switching device, power supply path-switching system, and power supply path-switching method

This power feed line switching circuit for switching connection states among a plurality of power feed lines has a plurality of switching circuits, and a variable resistance unit. The switching circuits switch the connection states among the power feed lines. The variable resistance unit is disposed on the connecting paths among the power feed lines before and after the switching, and the resistance values thereof change in conjunction with operations of the switching circuits.

Power feed line switching circuit, branching device, submarine cable system, and power feed line switching method

An optical relay device is provided which is capable of outputting control signal light without equipping a light source for the control signal light and capable of flexibly managing and changing a wavelength of the control signal light in accordance with a state of a network. The optical relay device includes an optical receiving unit that receives a wavelength multiplexed optical signal, a control unit that specifies a first wavelength and outputting notification information, and a processing unit that selects an optical signal having the first wavelength from the received wavelength multiplexed optical signal, applying intensity-modulation in accordance with the notification information to the selected optical signal, adding the intensity-modulated optical signal back to the wavelength multiplexed optical signal, and outputting the wavelength multiplexed optical signal.

Optical relay device, optical communication system, optical relay method, and storage medium

Aspects of the present disclosure describe systems, structures and methods providing fully reconfigurable optical add-drop multiplexing (ROADM) that provide redundancy protection against any two (2) simultaneous wavelength selective switch (WSS) failures with only four 2&#xd7;1 WSS structures for both Eastbound and Westbound traffic, while not requiring bidirectional operation of the WSS structures.

Redundancy protection for reconfigurable optical add/drop multiplexing (ROADM) branching unit

Systems and methods for data transport, including submarine reconfigurable optical add/drop multiplexers, branching units configured to receive signals from trunk terminals (TTs), and dummy light filters configured to pass useful signals through the filters, and to reflect dummy light. Optical interleavers are configured to separate useful signals into two or more groups of optical channels, and the optical channels are set to a frequency of either a left or a right portion of a total channel bandwidth. De-interleavers merge signal groups together from trunk terminals, and lasers at each of the transponders at the source terminals are configured to adjust a destination of a channel by fine tuning a frequency or wavelength of the one or more signals.

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Tokyo, Japan

Ryuji Aida