公开(公告)号：US20230142562A1

公开(公告)日：2023-05-11

申请号：US17917597

申请日：2020-04-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hirotaka UJIKAWA ,  Rintaro HARADA ,  Shin KANEKO

IPC: H04B10/032 ,  H04B10/275 ,  H04L43/0864

CPC classification number: H04B10/032 ,  H04B10/2755 ,  H04L43/0864

Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. First and second slave station devices are slave station devices that cannot perform communication via the normal path. The magnitude relationship between backup path RTTs is opposite to the magnitude relationship between normal path RTTs. If the second normal path RTT for the second slave station device is longer than the first normal path RTT for the first slave station device, the first backup path RTT is longer than the second backup path RTT, and the second backup path RTT is shorter than the first backup path RTT. Based on this fact, the master station device limits the QuietWindow, which is used in ranging processing for measuring the backup path RTT, to a size smaller than a predetermined maximum size.

公开(公告)号：US20230155712A1

公开(公告)日：2023-05-18

申请号：US17908223

申请日：2020-03-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hirotaka UJIKAWA ,  Shin KANEKO ,  Jun TERADA

IPC: H04J14/02 ,  H04B10/272

CPC classification number: H04J14/0206 ,  H04B10/272 ,  H04J14/0213

Abstract: A wavelength multiplexing communication system includes a master station apparatus and a plurality of slave station apparatuses. The master station apparatus includes a wavelength multiplexing communication unit that performs wavelength multiplexing communication with the plurality of slave station apparatuses by wavelengths the number of which is equal to or less than the number of the plurality of slave station apparatuses using an optical signal of a wavelength in a first wavelength group and an optical signal of a wavelength in a second wavelength group. The slave station apparatuses include an optical communication unit that performs communication of the main signal with the master station apparatus by an optical signal of a wavelength in the first wavelength group, which is different from a wavelength in the first wavelength group used by another slave station when the main signal communication is performed in the host slave station apparatus, and performs communication of a signal other than the main signal with the master station apparatus by an optical signal of a wavelength in the second wavelength group, which is a wavelength same as a wavelength used by another slave station apparatus when the main signal communication is not performed in the host slave station apparatus.

公开(公告)号：US20240283817A1

公开(公告)日：2024-08-22

申请号：US18563932

申请日：2021-05-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Naotaka SHIBATA ,  Shin KANEKO

IPC: H04L9/40

CPC classification number: H04L63/1458

Abstract: A switch in a communication network comprises a controller for controlling a communication flow in the communication network. A suspected flow is a communication flow suspected of being related to a DDoS (Distributed Denial of Service) attack. A normal flow is a communication flow other than the suspected flow. The controller is configured to execute provisional handling when receiving a provisional handling instruction indicating identification information of the suspected flow from a network controller. The provisional handling includes processing of setting a priority of the suspected flow to a designated priority, and processing of setting a priority of the normal flow higher than the designated priority.

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：US20230198613A1

公开(公告)日：2023-06-22

申请号：US17916789

申请日：2020-04-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hirotaka UJIKAWA ,  Shin KANEKO ,  Jun TERADA

IPC: H04B10/032

CPC classification number: H04B10/032

Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is a slave station device that cannot perform communication via the normal path. If the first slave station device is detected, the master station device calculates a first backup path for the first slave station device based on a first RTT between the master station device and the loop path, a loop RTT required for one full lap on the loop path, and the first normal path RTT for the first slave station device. The master station device then resumes communication control processing for the first slave station device based on the calculated first backup path RTT.

公开(公告)号：US20240187094A1

公开(公告)日：2024-06-06

申请号：US18285496

申请日：2021-04-05

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04B10/112 ,  H04B10/516 ,  H04L1/00

CPC classification number: H04B10/112 ,  H04B10/5161 ,  H04L1/0061

Abstract: A beam transmission device transmits a directional beam toward a beam reception device in a wireless communication system. The main signal generation unit generates a main signal. A control signal generation unit periodically generates a control signal related to maintaining communication with the beam reception device. A signal multiplexing unit multiplexes the main signal and the control signal. A divergence angle adjustment unit sets a target divergence angle to a first divergence angle in a period in which the control signal is not included in the multiplexed signal, and sets the target divergence angle to a second divergence angle larger than the first divergence angle in a period in which the control signal is included in the multiplexed signal. A beam control unit changes a divergence angle of the beam modulated by the multiplexed signal to the target divergence angle.

公开(公告)号：US20230308179A1

公开(公告)日：2023-09-28

申请号：US18022196

申请日：2020-08-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Rintaro HARADA ,  Shin KANEKO

IPC: H04B10/11 ,  H04B10/294

CPC classification number: H04B10/11 ,  H04B10/294

Abstract: A spatial optical communication system in which a plurality of transmitters and a plurality of receivers opposite to each of the plurality of transmitters perform an optical communication in parallel, in which the plurality of transmitters transmit optical signals of same or adjacent wavelengths to the receivers of each opposite location, and has an interference blocking unit which is disposed between the transmitter and the receiver and spatially blocks an optical signal that interferes with the receiver of a non-opposite location among optical signals transmitted from the transmitter to the receiver of an opposite location. As a result, it is possible to avoid interference with other optical communications with a reduced space and at low cost, without need to supply power.

公开(公告)号：US20230155674A1

公开(公告)日：2023-05-18

申请号：US17916755

申请日：2020-04-09

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hirotaka UJIKAWA ,  Shin KANEKO ,  Jun TERADA

IPC: H04B10/035 ,  H04B10/032 ,  H04B10/278 ,  H04J14/08

CPC classification number: H04B10/035 ,  H04B10/032 ,  H04B10/278 ,  H04J14/08

Abstract: The present invention enables shortening the time required for resuming communication in a protection method that uses a backup path in an optical communication system that includes a master station device and multiple slave station devices. The slave station devices are connected to a loop path in parallel. The communication paths between the master station device and the slave station devices include a normal path and a backup path. The master station device executes communication control processing with respect to the slave station devices based on the RTTs. A first slave station device is one of the slave station devices, and a second slave station device is a slave station device that cannot perform communication via the normal path. If a second slave station device is detected, the master station device calculates a second backup path RTT for the second slave station device based on the first normal path RTT and the first backup path RTT for the first slave station device and a second normal path RTT for the second slave station device. The master station device then resumes communication control processing for the second slave station device based on the calculated second backup path RTT.

公开(公告)号：US20230094895A1

公开(公告)日：2023-03-30

申请号：US17908457

申请日：2020-03-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hirotaka UJIKAWA ,  Shin KANEKO ,  Jun TERADA

IPC: H04B10/272 ,  H04J14/02

Abstract: A wavelength multiplexing communication system includes a master station apparatus and a plurality of slave station apparatuses. The master station apparatus includes a wavelength multiplexing communication unit. The wavelength multiplexing communication unit performs wavelength multiplexing communication with the plurality of slave station apparatuses by using optical signals having the number of wavelengths equal to or less than the number of the plurality of slave station apparatuses. The slave station apparatus includes an optical communication unit. When the main signal communication is performed in the host slave station apparatus, the optical communication unit communicates with the master station apparatus by an optical signal having the same wavelength as a wavelength used by another slave station apparatus in which a main signal notification is not performed.

公开(公告)号：US20220278765A1

公开(公告)日：2022-09-01

申请号：US17622025

申请日：2019-06-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hiroyuki UZAWA ,  Hirotaka NAKAMURA ,  Jun TERADA

IPC: H04J14/02 ,  H04L47/62 ,  H04L47/56

Abstract: A transfer device includes: a frame information acquisition unit configured to monitor downstream frames between host devices and OLTs and calculate a statistical value of the downstream frames per a fixed cycle; a frame storage unit configured to store the downstream frames in a plurality of queues; a frame sorting unit configured to input the downstream frames to the queues; and a distribution control unit configured to determine the number of frames to be sequentially input to the queues and increase the number of distributed frames of at least one of the host devices input to an OLT, the OLT having a smaller value of a total number of frames input from all the host devices than a maximum number of rounded frames obtained by dividing a value of a total number of frames input until the frames of all the host devices take turns around the plurality of queues by the number of OLTs. As a result, a delay requirement can be satisfied while a memory size of the queue and power consumption required for the frame sorting process are reduced.