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：US20230140715A1

公开(公告)日：2023-05-04

申请号：US17913388

申请日：2020-03-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Hirotaka UJIKAWA

IPC: H04B10/27

Abstract: An optical transmission device which performs relaying between a terminal device and a server via an optical network device, the terminal device and the server establishing connection with each other, includes a request detection unit which detects a connection establishment request transmitted to the server by the optical network device on the basis of a connection establishment request transmitted to the server by the terminal device, a response detection unit which detects an acknowledgment transmitted to the terminal device by the server on the basis of the connection establishment request detected by the request detection unit, and a band allocation unit which, if the response detection unit detects the acknowledgment, performs allocation so as to expand a band over which the optical network device is capable of transmission to the server, regardless of presence or absence of a buffer amount notification to be transmitted by the optical network device.

公开(公告)号：US20230088621A1

公开(公告)日：2023-03-23

申请号：US17908416

申请日：2020-03-02

Applicant: Nippon Telegraph and Telephone Corporation

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

IPC: H04B10/03

Abstract: In an optical communication system, an optical communication device and a plurality of optical transmission devices are loop-connected via transmission line. An optical signal transmission unit of the optical communication device, when no communication interruption occurs in the transmission line, outputs an optical signal addressed to a communication destination device being another optical communication device that communicates with the own device to a transmission line connected to either one of two neighboring optical transmission devices. The optical signal transmission unit outputs, at the time of communication interruption occurring in the transmission line, an optical signal addressed to the communication destination device to both of transmission lines connected to respective two neighboring optical transmission devices. A branch unit of the optical transmission device branches the optical signal input from a neighboring device that is the neighboring optical communication device or another optical transmission device, and outputs branched optical signals to a transmission line connected to a neighboring device different from the neighboring device transmitted the optical signal and a transmission line connected to a subordinate communication destination device of the own device.

公开(公告)号：US20250150387A1

公开(公告)日：2025-05-08

申请号：US18838124

申请日：2022-02-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tomoya HATANO ,  Hiroshi O ,  Takashi YAMADA ,  Hirotaka UJIKAWA ,  Yushi KOYASAKO

IPC: H04L45/302 ,  H04L45/121 ,  H04L45/42

Abstract: Provided is a communication system in which a plurality of networks each having a detour within an end-to-end distance are formed, the communication system including: a plurality of section control units that perform path control for each of sections with a network having a detour, the sections being obtained by partitioning the communication system; and an integrated control unit that controls the plurality of section control units, in which the integrated control unit includes an optimization unit that determines an optimal guaranteed delay time for each section to satisfy an end-to-end guaranteed delay time provided by a service, and a notification unit that notifies the plurality of section control units of the optimal guaranteed delay time for each section determined by the optimization unit, and the plurality of section control units each include a switching destination instruction unit that instructs a switching destination to switch to a path satisfying the optimal guaranteed delay time notified from the integrated control unit.

公开(公告)号：US20240405909A1

公开(公告)日：2024-12-05

申请号：US18694838

申请日：2021-10-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroko NOMURA ,  Hirotaka UJIKAWA ,  Kenji MIYAMOTO ,  Kota ASAKA ,  Yoshihito SAKAI ,  Tatsuya SHIMADA

IPC: H04J14/02

Abstract: A control device includes an acquisition unit that acquires information from a distributed station that notifies the information related to one or more events occurred within a predetermined time period at a predetermined notification frequency, an information analysis unit that executes analysis processing on the information, a frequency derivation unit that derives an occurrence frequency of the information, a load derivation unit that derives a load of analysis processing of the information, and a frequency control unit that controls the predetermined notification frequency with a frequency lower than the occurrence frequency as an upper limit on the basis of at least one of an analysis result of the information, an occurrence frequency of the information, and a load of analysis processing of the information.

公开(公告)号：US20230421934A1

公开(公告)日：2023-12-28

申请号：US18037072

申请日：2020-11-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Yoshihito SAKAI

IPC: H04Q11/00 ,  H04B10/032

CPC classification number: H04Q11/0067 ,  H04B10/032 ,  H04Q2011/0081

Abstract: Provided are a communication control device, a communication control system, a communication control method, and a communication control program that make it difficult to reduce band utilization efficiency. In an OLT server 9b that is a communication control device, a transmission time storage unit 12 stores a transmission time of an optical signal between each ONU 3 and OLT 4. An optical transmission control unit 13 generates control information for controlling transmission start and transmission end of optical signals in each ONU 3. A failure detection suppression unit 15 calculates a first time at which the reception of the optical signal from an ONU 3p ends using control information and a transmission time. The failure detection suppression unit 15 calculates a second time at which synchronization processing ends after the reception of the optical signal from an ONU 3q that transmits the optical signal next after the ONU 3p is started using the synchronization time until the synchronization processing acquired by a synchronization time acquisition unit 14 ends. The failure detection suppression unit 15 causes the failure detection unit 11 that detects a link failure in an OLT 4 to suppress detection of a link failure from the first time to the second time.

公开(公告)号：US20230327756A1

公开(公告)日：2023-10-12

申请号：US18024926

申请日：2020-09-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04B10/079

CPC classification number: H04B10/079

Abstract: Provided is a communication monitoring device and a communication monitoring system capable of monitoring a state of a connection device that forms an optical path by using an optical passive component. A communication management device (8) of a communication monitoring system (1) includes a plurality of photodetectors (11), a plurality of recognition units (14), a processing unit (15), and a transmission unit (16). The photodetectors (11) are provided in a connection device (6). The connection device (6) connects a plurality of optical communication lines (3) by using an optical passive component to form a plurality of optical paths through which optical signals pass. Each photodetector (11) detects an optical signal passing through the corresponding optical path. Each recognition unit (14) recognizes a state of detection of the optical signal by the corresponding photodetector (11). The processing unit (15) generates information regarding a communication state of the connection device (6) on the basis of information regarding the state of detection recognized by each recognition unit (14). The transmission unit (16) transmits the information regarding the communication state of the connection device (6) generated by the processing unit (15) to a receiving unit (9) outside a communication monitoring device (7).

公开(公告)号：US20230327755A1

公开(公告)日：2023-10-12

申请号：US18024939

申请日：2020-09-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04B10/07

CPC classification number: H04B10/07

Abstract: Provided is a communication monitoring system capable of monitoring a state of a connection device that forms an optical path by using an optical passive component. A communication monitoring system (1) includes a plurality of photodetectors (9) provided in a connection device (6), a plurality of recognition units (13), a processing unit (14), a light emitting unit (15), a mixing unit (12), a separation unit (16), a collection unit (17), and a management unit (18). The photodetector (9) detects an optical signal passing through a corresponding optical path. The recognition unit (13) recognizes a state of detection by the corresponding photodetector (9). The processing unit (14) generates information regarding a communication state of the connection device (6) on the basis of the recognition by each recognition unit (13). The light emitting unit (15) converts the generated information into a monitoring signal that is an optical signal and transmits the monitoring signal. The monitoring signal is passed through an optical communication line (3) as a mixed signal by the mixing unit (12) and is separated from the mixed signal by the separation unit (16). The collection unit (18) outputs the separated monitoring signal to the management unit (18) that manages a state of a PON (2).

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：US20230145000A1

公开(公告)日：2023-05-11

申请号：US17914849

申请日：2020-03-30

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Hirotaka UJIKAWA

IPC: H04W24/08 ,  H04W76/10 ,  H04W40/12

CPC classification number: H04W24/08 ,  H04W76/10 ,  H04W40/12 ,  H04W80/06

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 smaller than a congestion window, transmits a command that sets the client to lower a slow start threshold to a predetermined value, or a command that sets the server to lower a window size to a predetermined value, regardless of whether or not a timeout occurs.