公开(公告)号：US20250016479A1

公开(公告)日：2025-01-09

申请号：US18708949

申请日：2021-12-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takuya KANAI ,  Shin KANEKO ,  Naotaka SHIBATA ,  Junichi KANI ,  Tomoaki YOSHIDA

IPC: H04Q11/00 ,  H04B10/27

Abstract: An optical node device to which a first subscriber device and a second subscriber device are connected in an optical communication system in which the first subscriber device and the second subscriber device are mixed, the first subscriber device being connected by one core using different wavelengths in transmission and reception, the second subscriber device being connected by two cores using the same wavelength in transmission and reception, the optical node device including: a transmission/reception separator that transfers an optical signal transmitted from the first subscriber device and an optical signal addressed to the first subscriber device without interference; and an optical switch that controls a connection relationship between ports such that an optical signal transmitted from the first subscriber device or an optical signal addressed to the first subscriber device passes through the transmission/reception separator and an optical signal transmitted from the second subscriber device or an optical signal addressed to the second subscriber device does not pass through the transmission/reception separator, and outputs an optical signal input from a certain optical transmission line from another optical transmission line.

公开(公告)号：US20250008248A1

公开(公告)日：2025-01-02

申请号：US18709754

申请日：2021-11-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yasunari TANAKA ,  Takuya KANAI ,  Kazutaka HARA ,  Yumiko SENOO ,  Shin KANEKO ,  Junichi KANI

IPC: H04Q11/00 ,  H04L41/12 ,  H04L43/0864

Abstract: An optical switch having a plurality of ports outputs an optical signal received from a first port that is one of the plurality of ports connected to an optical communication device from a second port that another one of the plurality of ports according to a transmission path of an optical signal. An optical branching part branches an optical signal which has been output from a second port in accordance with a branching ratio. A measurement part measures a round trip time by transmitting and receiving an optical signal to and from an optical communication device through an optical switch, and calculates a transmission distance of the optical signal on the basis of the measured round trip time. An instruction part instructs, the optical branching part, of the branching ratio determined on the basis of the calculated transmission distance.

公开(公告)号：US20240089009A1

公开(公告)日：2024-03-14

申请号：US18274266

申请日：2021-02-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Sang-Yuep KIM ,  Junichi KANI

IPC: H04B10/61 ,  H04L27/02 ,  H04L27/26

CPC classification number: H04B10/6165 ,  H04L27/02 ,  H04L27/2665

Abstract: The communication device includes: a reception unit that receives burst frame signals from a plurality of other communication devices respectively; and a control unit that changes a block length of a moving average filter in carrier phase synchronization so as to minimize a phase noise amount of the burst frame signals.

公开(公告)号：US20240056709A1

公开(公告)日：2024-02-15

申请号：US18275111

申请日：2021-08-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yumiko SENOO ,  Junichi KANI ,  Kazutaka HARA ,  Shin KANEKO ,  Ryo KOMA

IPC: H04Q11/00

CPC classification number: H04Q11/0062 ,  H04Q2011/0084

Abstract: An optical switch having a plurality of ports outputs an optical signal, which is input from one of the plurality of ports, from another port. A quality compensator perform quality compensation of the optical signal output from the optical switch, and input the quality-compensated optical signal to the optical switch. A controller selects, among the plurality of quality compensators, a quality compensator that performs quality compensation according to the degree of quality deterioration of the optical signal when the optical signal input from a predetermined port of the optical switch is transmitted through a transmission path. The controller controls the optical switch so that the optical signal, in which quality is compensated by the selected quality compensator through the optical signal input from the predetermined port being output to the selected quality compensator, is output from the port corresponding to a transmission destination of the optical signal.

公开(公告)号：US20220368428A1

公开(公告)日：2022-11-17

申请号：US17623968

申请日：2019-07-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Ryo IGARASHI ,  Takuya KANAI ,  Masamichi FUJIWARA ,  Junichi KANI

IPC: H04B10/67 ,  H04B10/61

Abstract: An optical reception device including: a wavelength selection unit configured to split an optical signal amplified by an optical amplifier into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and control a passage state of a passage target optical switch through which the optical signal is to be passed, out of a plurality of optical switches provided on the respective paths, to select an optical signal of a path where the optical signal entered and output the optical signal to a receiver; and a wavelength detection unit configured to detect the wavelength of an optical signal by using each of a plurality of optical detectors, determine the passage target optical switch based on a detection result, and output, to the determined passage target optical switch, a control signal for controlling the passage target optical switch so as to enter the passage state, the optical detectors being respectively provided on different paths that are different from the paths on which the plurality of optical switches are provided and that respectively correspond to wavelengths into which the optical signal is split by a wavelength multiplexer/demultiplexer.

公开(公告)号：US20210336706A1

公开(公告)日：2021-10-28

申请号：US17273282

申请日：2019-08-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Noriko IIYAMA ,  Masamichi FUJIWARA ,  Junichi KANI

IPC: H04B10/69 ,  H04B10/61

Abstract: An ADC (12) in an optical receiver (1) generates a sample signal composed of time series samples by oversampling a received signal that is an electrical signal converted from an optical signal by a light receiving unit (11). A symbol timing detection unit (132) of a DSP unit (13) detects a symbol timing in the sample signal. When it is determined that a symbol timing is appearing at a longer interval than a predetermined interval based on this detection result, a symbol timing adjusting unit (133) skips one or more samples included in the sample signal to read out samples at the predetermined interval, while when it is determined that the symbol timing is appearing at a shorter interval than the predetermined interval, the symbol timing adjusting unit inserts the same samples as one or more samples included in the sample signal immediately after the one or more samples to read out the samples at the predetermined interval.

公开(公告)号：US20240187099A1

公开(公告)日：2024-06-06

申请号：US18285926

申请日：2021-04-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shin KANEKO ,  Junichi KANI ,  Kazutaka HARA ,  Takuya KANAI

IPC: H04B10/27 ,  H04B10/58

CPC classification number: H04B10/27 ,  H04B10/58

Abstract: An optical switch receives an input of an optical signal which has been transmitted by a first optical communication device from a first port, and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and a second optical communication device is set. An optical branching unit branches a part of the optical signal which has been transmitted through the first optical transmission line, and outputs the branched optical signal to a second optical transmission line. An optical transmitting and receiving apparatus includes a reception unit, a transmission unit, and a light cutoff unit. The reception unit receives an input of the optical signal which has been branched by the optical branching unit from the second optical transmission line, and acquires a signal addressed to a destination different from the second optical communication device from the input optical signal. The transmission unit generates an optical signal using light emitted by a light source. The light cutoff unit prevents the light from the light source from being input to the second optical transmission line.

公开(公告)号：US20230421257A1

公开(公告)日：2023-12-28

申请号：US18039425

申请日：2020-12-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takeshi IMAI ,  Junichi KANI ,  Shin KANEKO ,  Naotaka SHIBATA ,  Rintaro HARADA

IPC: H04B10/112 ,  H04B10/50 ,  H04B10/60

CPC classification number: H04B10/112 ,  H04B10/503 ,  H04B10/60

Abstract: An optical transmitter (3) tracks a moving body (1) and irradiates the moving body (1) with a laser beam (4). An optical receiver (5) is mounted on the moving body (1), receives the laser beam (4), and performs optical space communication with the optical transmitter (3). The optical transmitter (3) extends an irradiation range (6) of the laser beam (4) into an elliptical shape.

公开(公告)号：US20230208530A1

公开(公告)日：2023-06-29

申请号：US17928476

申请日：2020-06-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masamichi FUJIWARA ,  Junichi KANI

IPC: H04B10/64

CPC classification number: H04B10/64

Abstract: Provided is an optical receiver including: a heterodyne detection unit that converts, by heterodyne detection, a subcarrier multiplexed signal in which a plurality of optical signals transmitted from a plurality of optical transmitters are multiplexed, into an electrical signal in an intermediate frequency band; a filter unit that removes a carrier component from the electrical signal in the intermediate frequency band, generated by the conversion, to extract a subcarrier component; an analog-digital conversion unit that performs analog-digital conversion on a signal having the subcarrier component, extracted by the filter unit; and a digital signal processing unit that performs digital signal processing for each subcarrier on a digital signal generated by the analog-digital conversion performed by the analog-digital conversion unit.

公开(公告)号：US20230163856A1

公开(公告)日：2023-05-25

申请号：US17921253

申请日：2020-05-01

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takuya KANAI ,  Shin KANEKO ,  Kazuaki HONDA ,  Junichi KANI ,  Hiroo SUZUKI ,  Jun TERADA

IPC: H04B10/60 ,  H04B10/077

CPC classification number: H04B10/60 ,  H04B10/077

Abstract: An optical signal processing apparatus includes a removal unit and a superimposition unit. The removal unit receives, from a first optical transmission path, an optical signal converted from an electrical signal, in which a first signal and a second signal having different frequencies from each other have been superimposed, and removes the second signal from the optical signal which has been input. The superimposition unit superimposes a third signal having a frequency different from a frequency of the first signal on the optical signal in which the second signal has been removed by the removal unit, and outputs the optical signal in which the third signal has been superimposed to a second optical transmission path.