公开(公告)号：US20250081270A1

公开(公告)日：2025-03-06

申请号：US18697561

申请日：2021-10-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Yuka OKAMOTO ,  Tatsuya SHIMADA ,  Yoshihito SAKAI ,  Hirotaka UJIKAWA ,  Kenji MIYAMOTO ,  Hiroko NOMURA

IPC: H04W76/20 ,  H04W28/02 ,  H04W28/08 ,  H04W72/52

Abstract: A switching control apparatus calculates a traffic amount in a predetermined period of each first transmission apparatus that is a transmission apparatus of a predetermined layer on the basis of allocation of radio resources to a terminal that wirelessly transmits a signal to a lowermost transmission apparatus among a plurality of transfer apparatuses that constitute a communication network hierarchized into a plurality of layers and transfer a received signal to a layer next above. The switching control apparatus calculates a processing capability predicted to be required for each second transmission apparatus which is a transmission apparatus of a layer next above the first transmission apparatus on the basis of the traffic amount of the first transmission apparatus. The switching control apparatus instructs a transfer apparatus for transferring a signal transmitted from the first transmission apparatus to the second transmission apparatus to switch a connection destination of the first transmission apparatus under the control of the second transmission apparatus in which congestion is determined to occur on the basis of the processing capability.

公开(公告)号：US20230275682A1

公开(公告)日：2023-08-31

申请号：US18015435

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04J14/08

CPC classification number: H04J14/08

Abstract: A communication device includes: a communication unit that is connected to an optical ring network, conducts optical signal communication by time-division multiplexing, and receives a control signal for controlling an optical signal transmission timing from a master communication device; and a determination unit that determines the master communication device not to be operating properly and causes the subject communication device to operate as a new master communication device, in a case where the control signal is not received in a predetermined period. Thus, even in a case where the master device cannot operate properly, a slave device operates as the master device, so that the system operation can be continued.

公开(公告)号：US20230170990A1

公开(公告)日：2023-06-01

申请号：US17921569

申请日：2020-05-12

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04B10/035 ,  H04B10/079

CPC classification number: H04B10/035 ,  H04B10/0795

Abstract: Time taken for resuming communication in a protection scheme using a backup path in an optical communication system including a master station device and a plurality of slave station devices is decreased. The plurality of slave station devices are connected in parallel to a looped path. A communication path between the master station device and each of the slave station device includes a normal path and a backup path. The master station device performs communication control processing for each of the slave station device based on RTT. A first slave station device is a slave station device with which communication through the normal path has become impossible. First backup path RTT of the first slave station device is calculated based on first normal path RTT of the first slave station device, first partial RTT between the master station device and the looped path, and loop propagation time necessary for one trip through the looped path. The communication control processing for the first slave station device is resumed based on the calculated first backup path RTT without measurement of the first backup path RTT when the first slave station device is sensed.

公开(公告)号：US20230120832A1

公开(公告)日：2023-04-20

申请号：US17907426

申请日：2020-03-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Hirotaka UJIKAWA

IPC: H04W24/08 ,  H04W76/10 ,  H04W28/02

Abstract: A monitoring device that monitors a network to which a plurality of terminal devices establishing a connection based on TCP are connected, includes: a request detection unit that detects a connection establishment request that a terminal device becoming a client sends to another terminal device becoming a server; an available bandwidth calculation unit that calculates an available bandwidth by subtracting a current amount of traffic from an allowable communication capacity, for each communication path identified by the connection establishment request detected by the request detection unit; and a setting command unit that, when the available bandwidth calculated by the available bandwidth calculation unit is larger than a preset value, transmits a command that sets the client to enlarge a congestion window to a predetermined value, regardless of presence or absence of an acknowledgement sent by the server.

公开(公告)号：US20220417914A1

公开(公告)日：2022-12-29

申请号：US17269211

申请日：2019-08-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroyuki UZAWA ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04W72/04 ,  H04W28/20 ,  H04W72/12

Abstract: A bandwidth allocation apparatus includes an acquisition unit acquiring scheduling information related to transmission of uplink data from a first subscriber line termination apparatus corresponding to a subscriber line termination apparatus needing to transfer uplink data with low latency, a requested amount reception unit receiving, from second subscriber line termination apparatus corresponding to a subscriber line termination apparatus not needing to transfer uplink data with low latency, information representing a requested amount related to transmission of uplink data from the second subscriber line termination apparatus, in a requested amount reception cycle corresponding to a cycle equal to or longer than a predetermined maximum round-trip time, and an allocation unit allocating, in an allocation amount determination cycle shorter than the requested amount reception cycle, a bandwidth to the uplink data from the first subscriber line termination apparatus on a basis of the scheduling information, and allocating, in the allocation amount determination cycle, a bandwidth to the uplink data from the second subscriber line termination apparatus on a basis of the information representing the requested amount.

公开(公告)号：US20210112016A1

公开(公告)日：2021-04-15

申请号：US17057034

申请日：2019-05-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hiroyuki UZAWA ,  Hirotaka NAKAMURA ,  Daisuke HISANO ,  Hirotaka UJIKAWA ,  Jun TERADA

IPC: H04L12/865

Abstract: A transfer apparatus include a distribution unit, a storage unit, and a transfer unit, in which the distribution unit is configured to identify a plurality of networks to which frames belong, distribute the frames for each of the networks based on an identification result, and store the distributed frames in the storage unit, the storage unit is configured to store information of a time at which a frame of the frames is stored in the storage unit and the frame in association with each other, and the transfer unit is configured to detect a period of time for which the frame stays in the storage unit, detect a remaining period to send which is a remaining time of a time for which the frame is permitted to stay in the storage unit, for each of the frames, based on a difference between the time for which the frame stays in the storage unit and the delay upper limit value, and output the frame to a predetermined apparatus based on the remaining period to send.

公开(公告)号：US20250142363A1

公开(公告)日：2025-05-01

申请号：US18865963

申请日：2022-05-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Karin UMEDA ,  Yoshihito SAKAI ,  Hiroko NOMURA ,  Hirotaka UJIKAWA ,  Tatsuya SHIMADA

IPC: H04W24/02 ,  H04W36/22 ,  H04W52/02

Abstract: Provided is a communication system including: one or more wireless stations that perform wireless communication with one or more terminals; a plurality of distributed stations connected, directly or via another device, to the one or more wireless stations; a cooperation information collection unit that acquires, at a predetermined cycle, cooperation information indicating a state of communication between the plurality of distributed stations and the one or more terminals; an optical path switching control unit that controls switching of an optical path between the one or more wireless stations and the plurality of distributed stations when it is determined, on the basis of the cooperation information, that the switching of the optical path between the one or more wireless stations and the plurality of distributed stations is required; and a sleep control unit that causes each of the distributed stations that can sleep to transition to a sleep state after the switching of the optical path is performed.

公开(公告)号：US20240014897A1

公开(公告)日：2024-01-11

申请号：US18025370

申请日：2020-09-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Sei KOU ,  Tomoya HATANO ,  Hirotaka UJIKAWA ,  Yuka OKAMOTO

IPC: H04B10/077

CPC classification number: H04B10/0771

Abstract: An optical sensor (3) is installed in an optical path control device (1) that controls an optical path (2) without using an electrical element. The optical sensor (3) detects an optical signal passing through the optical path (2). A communication state determination unit (5) determines a communication state of the optical path (2) based on detection of the optical signal by the optical sensor (3). A position information reception management unit (10) receives and stores position information of the optical path control device (1). An information arrangement unit (6) collectively converts a determination result of the communication state determination unit (5) and the position information into information. A transmission unit (7) transmits the information.

公开(公告)号：US20230362520A1

公开(公告)日：2023-11-09

申请号：US18024857

申请日：2020-09-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hirotaka UJIKAWA ,  Tomoya HATANO ,  Yuka OKAMOTO ,  Sei KOU

IPC: H04B10/032 ,  H04Q11/00

CPC classification number: H04Q11/0067 ,  H04B10/032 ,  H04Q11/0005 ,  H04L41/0677 ,  H04Q2011/0092

Abstract: An optical communication system includes a looped path in which an active trunk fiber and a standby trunk fiber are connected in a loop. A plurality of optical combining/splitting units is provided on an active trunk fiber in series, and a plurality of slave devices is connected the plurality of optical combining/splitting units, respectively. A master device performs optical communication with each slave device. Each optical combining/splitting unit includes an optical sensor configured to detect an optical signal passing through an optical fiber and a transmitter. The transmitter determines whether or not there is an abnormality in optical communication on the basis of a detection state of the optical signal and transmits an abnormality notification including identification information of the optical combining/splitting unit to a monitoring apparatus in a case where there is an abnormality. The monitoring apparatus holds connection relationship information indicating a connection relationship between the plurality of optical combining/splitting units along the active trunk fiber. In a case where the monitoring apparatus receives the abnormality notification from at least one of the plurality of optical combining/splitting units, the monitoring apparatus specifies a failure position on a communication path on the basis of identification information of each optical combining/splitting unit that has transmitted the abnormality notification and the connection relationship information.

公开(公告)号：US20230318730A1

公开(公告)日：2023-10-05

申请号：US18015680

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04J14/02

CPC classification number: H04J14/0227 ,  H04J14/0201

Abstract: A communication device that is connected to a wavelength-multiplexed optical ring network and conducts communication by performing time-division multiplexing on an optical signal for each wavelength includes: a communication unit that transmits a requested transmission amount for requesting a transmission band to a master communication device, and receives an allowed transmission amount for allocating a transmission band from the master communication device; and a control unit that estimates a band utilization rate of each wavelength on the basis of the requested transmission amount and the allowed transmission amount, and allocates data to the respective wavelengths so as to equalize the band utilization rates among the wavelengths. Thus, it is possible to equalize band utilization rates among wavelengths, and enhance communication efficiency of the entire system.