Nec Corporation

Yoshinari Takigawa

Fatih Yaman

Yoshihisa Inada

Shinsuke Fujisawa

Takanori Inoue

Kohei Nakamura

Ryuji Aida

Eduardo Rodriguez

Hussam Batshon

Ryu Kurahashi

In order to improve the flexibilities of structures to be added, a submarine optical cable system according to the present invention comprises a first switching device connected to a first land station by means of a first submarine optical cable, a second switching device connected to a second land station by means of a second submarine optical cable, and a third submarine optical cable connected to the first switching device and to the second switching device, wherein the first switching device comprises a first optical fiber core connecting unit and a first optical switch group, and the second switching device comprises a second optical fiber core connecting unit and a second optical switch group.

Submarine optical cable system

In order to provide a grounding device and the like which can suppress generation of heat generated due to a rush current when a feed line is grounded, a grounding device according to the present invention comprises: an in-submarine-apparatus feed line which is installed in a submarine apparatus and which supplies power to an electrical component in the submarine apparatus; a determination means for determining whether or not the temperature of an impedance circuit which is to be connected between the feed line and a sea earth and which has a predetermined impedance exceeds a threshold value; and a first connection means for connecting two terminals of the impedance circuit when the temperature exceeds the threshold value as a result of the determination.

Grounding device, grounding method, and program recording medium

Provided are a junction device and an undersea cable system capable of saving a branch line when a problem involving ground fault occurs in a power feed line on a branch station side. This junction device is inserted into a power feed line and a transmission line connecting first and second trunk stations and a branch station, and includes a switching means for controlling a switch so as to connect the transmission line between the branch station and the first or second trunk station when a current detection means detects that there is no longer current flowing through the power feed line between a junction unit and the branch station and when a first optical signal detection means detects an optical signal in the transmission line connecting the junction unit and the branch station.

Junction device, and undersea cable system

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

In order to enable switching control over power-feeding paths even in the event of a ground fault or an open fault in a power-feeding path, the submarine branching unit is provided with: a switching circuit which switches multiple power-feeding paths formed among a first through a third power-receiving ports; a control circuit which receives power from a power-feeding path formed between the first power-receiving port and the second power-receiving port and controls the switching circuit; and a connection circuit which connects the control circuit between the third power-receiving port and a sea-earth when no power is supplied to the control circuit from the power-feeding path formed between the first power-receiving port and the second power-receiving port.

Submarine branching unit and submarine branching method

Provided are: a submarine cable system with which it is possible, with a simple configuration, to acquire the state of each of a plurality of high-voltage relays in a branching device; the branching device; and a state response method therefor. The branching device comprises: a plurality of interlocking relays respectively corresponding to a plurality of high-voltage relays for switching feeding paths; a drive unit which supplies drive electric currents supplied to the plurality of high-voltage relays to the plurality of corresponding interlocking relays, respectively; a state detection unit which detects operation states of the plurality of interlocking relays as the operation states of the plurality of high-voltage relays; and a response unit which, on the basis of the result of detection of the operation states of the plurality of interlocking relays, transmits the operation states of the plurality of high-voltage relays.

Submarine cable system, branching device, and state response method therefor

In order to improve the reliability of a reconfigurable optical add/drop multiplexing (ROADM) device, provided is an optical add/drop device that comprises the following: a first wavelength selection unit and a second wavelength selection unit that can select and output an optical signal of a prescribed wavelength from among inputted optical signals; a first branching unit that selectively outputs a first signal being an optical signal that has been inputted from a first terminal station on a main route to the first wavelength selection unit and the second wavelength selection unit; a second branching unit that selectively outputs a second signal being an optical signal that has been inputted from a second terminal station on a sub-route to the first wavelength selection unit and the second wavelength selection unit; and a first output unit that can selectively output to the second terminal station, as a third signal, either the optical signal outputted by the first wavelength selection unit on the basis of the first signal and the second signal, or the optical signal outputted by the second wavelength selection unit on the basis of the first signal and the second signal.

Optical add/drop device and optical add/drop method

In order to suppress both large current and arc discharge during hot switching, a grounding circuit includes a first relay, a second relay, and a third relay, a first resistance connected in series with the first relay and is capable of connecting the feeding path to the ground, and a voltage divider connected in series with the second relay and the third relay and is connectable in such a way as to divide voltage between the feeding path and the ground, the third relay being disposed at a point at which the voltage is divided, and when the feeding path is to be connected to the ground, the feeding path is connected to the ground via the first resistance by the first relay, the voltage divider is connected in parallel with the first relay and the first resistance, and a connection to the ground is cut off.

Grounding circuit and grounding method

In a feed line switching apparatus, a situation in which the feed line switching apparatus cannot work when feed lines have a predetermined connection relationship is prevented. The feed line switching apparatus includes a command acquisition unit which acquires a feed line switching command which designates a connection relationship of feed lines, a switching execution unit which switches the connection relationship of the feed lines in accordance with the feed line switching command acquired by the command acquisition unit, and a switching control unit which suppresses switching of the connection relationship of the feed lines in the switching execution unit for a predetermined feed line switching command.

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Tokyo, Japan

Yoshinari Takigawa