公开(公告)号：US12301295B2

公开(公告)日：2025-05-13

申请号：US18022932

申请日：2021-09-27

Applicant: NEC Corporation

Inventor： Yutaka Yano ,  Yoshihisa Inada ,  Takehiro Nakano ,  Ryuji Aida

IPC: H04B10/524 ,  H04B10/071 ,  H04B10/077 ,  H04J14/02 ,  H04J14/08

Abstract: 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.

公开(公告)号：US20230344521A1

公开(公告)日：2023-10-26

申请号：US18022932

申请日：2021-09-27

Applicant: NEC Corporation

Inventor： Yutaka YANO ,  Yoshihisa Inada ,  Takehiro Nakano ,  Ryuji Aida

IPC: H04B10/524 ,  H04J14/08

CPC classification number: H04B10/524 ,  H04J14/08

Abstract: 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.

公开(公告)号：US10594392B2

公开(公告)日：2020-03-17

申请号：US15747179

申请日：2016-08-01

Applicant: NEC CORPORATION

Inventor： Takehiro Nakano

IPC: H04B10/03 ,  H04B10/516 ,  H04B10/25 ,  H04J14/06

Abstract: To enable the transmission and reception of a super-channel optical signal to continue maintaining the possible transmission capacity without providing a redundant configuration in advance even though a failure occurs in a subcarrier, an optical transmitter 10 of the present invention includes a splitting means 20 for splitting an inputted client signal so as to make frequency efficiency in optical modulation means optimized; optical modulation means 31 to 3N for modulating one of subcarriers having mutually different wavelengths with the client signal output; a multiplexing means 40 for multiplexing the modulated signals and outputting a super-channel optical signal; and a control means 50, in a state where a failure occurs in one of the subcarriers, for making a split client signal output to modulation means corresponding to a subcarrier having no failure and applying a modulation method with a higher frequency efficiency to at least one of the modulation means.

公开(公告)号：US11483068B2

公开(公告)日：2022-10-25

申请号：US17294178

申请日：2019-11-12

Applicant: NEC Corporation

Inventor： Takehiro Nakano

IPC: H04B10/071 ,  H04B10/079

Abstract: Provided are an optical transmission line monitoring apparatus, an optical transmission line monitoring system, and an optical transmission line monitoring method capable of monitoring a plurality of optical transmission lines in parallel. A monitoring light output unit outputs monitoring lights with different frequencies to optical transmission lines. A local oscillation light source outputs a local oscillation light. An interference unit, to which return lights corresponding to the monitoring lights are input, configured to output an output light generated by interference between input lights and the local oscillation light. A conversion unit converts the output light into an electrical signal. A signal processing unit extracts, from the electrical signal, an intermediate-frequency signal based on each of the monitoring lights, and generates monitoring results of the optical transmission lines from the intermediate-frequency signal.

公开(公告)号：US11070305B2

公开(公告)日：2021-07-20

申请号：US16611274

申请日：2018-05-09

Applicant: NEC Corporation

Inventor： Takehiro Nakano

IPC: H04J14/02 ,  H01S3/00 ,  H01S3/067

Abstract: The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

公开(公告)号：US10338316B2

公开(公告)日：2019-07-02

申请号：US15504721

申请日：2015-08-19

Applicant: NEC Corporation

Inventor： Takehiro Nakano

IPC: H04B10/04 ,  G02B6/27 ,  G02F1/01 ,  H04B10/2543 ,  H04J14/04 ,  H04J14/06 ,  G02B6/293 ,  H04B10/532 ,  H04B10/58 ,  H04J14/02 ,  H04B10/50 ,  H04B10/61

Abstract: In order to provide a configuration for suppressing deterioration in the transmission quality of a signal light due to a nonlinear phenomenon in an optical fiber, a polarization dispersion adder is provided with: a polarization rotation unit which, with respect to each pulse of signal light generated by modulating a light carrier, rotates and outputs the polarization of the pulse during a period from a pulse rise start time (T0) to a pulse fall completion time (T1); and a delay addition unit which adds a delay of an amount corresponding to the rotation amount of the polarization added by the polarization rotation unit to the pulse outputted from the polarization rotation unit.