公开(公告)号：US20230261744A1

公开(公告)日：2023-08-17

申请号：US18015403

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04B10/079 ,  H04B10/077

CPC classification number: H04B10/0791 ,  H04B10/0771

Abstract: A communication device is connected to a wavelength-multiplexed optical ring network, and performs communication by performing time-division multiplexing on optical signals at each wavelength. In a case where a control signal transmitted from the master communication device is not received in a predetermined period, the communication device instructs a scheduler unit to suspend transmission of data at a failure wavelength that is the wavelength at which the host communication device has been determined not to be operating properly, also instructs the scheduler unit to transmit the data stored in the buffer of the failure wavelength at another wavelength, and suspends allocation of new data to the buffer of the failure wavelength. Thus, the delay in transmission of data at the failure wavelength can be shortened.

公开(公告)号：US20230247335A1

公开(公告)日：2023-08-03

申请号：US18024953

申请日：2020-09-11

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

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

IPC: H04Q11/00

CPC classification number: H04Q11/0067 ,  H04L45/28

Abstract: A plurality of optical sensors (3) are each installed in an optical path control device (1) that controls a corresponding one of the plurality of optical paths (2) without using an electrical element. Each of the plurality of optical sensors (3) detects an optical signal passing through the corresponding one of the plurality of optical paths (2). A transmitter (4) determines a communication state of the corresponding one of the plurality of optical paths (2) based on detection of the optical signal by the corresponding one of the plurality of optical sensors (3), and transmits information on the determined communication state. A power supplying optical signal generation unit (11) generates a power supplying optical signal. An optical signal synthesizing device (12) synthesizes the power supplying optical signal with the optical signal and transmits a signal obtained by the synthesis to the optical path control device (1). A storage battery (13) supplies electric power to the transmitter (1). A photoelectric conversion unit (14) converts the power supplying optical signal branched from the optical signal in the optical path control device (1) into an electrical output and supplies the electrical output to the storage battery (13).

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：US20230137775A1

公开(公告)日：2023-05-04

申请号：US17913197

申请日：2020-03-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Hirotaka UJIKAWA

IPC: H04W76/10 ,  H04L5/00

Abstract: A base station which performs relaying between a wireless terminal and a server, the wireless terminal 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 wireless terminal, a response detection unit which detects an acknowledgment transmitted to the wireless terminal 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 wireless terminal is capable of transmission to the server, regardless of presence or absence of a buffer amount notification from the wireless terminal.

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：US20220210718A1

公开(公告)日：2022-06-30

申请号：US17601849

申请日：2020-03-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Naotaka SHIBATA ,  Hiroyuki UZAWA ,  Hirotaka UJIKAWA ,  Yoichi FUKADA ,  Jun TERADA

IPC: H04W40/24 ,  H04L45/00 ,  H04L47/24 ,  H04W28/02

Abstract: A signal forwarding system includes: a plurality of signal forwarding devices forming a plurality of communication routes between a slave station and a master station; and a route control device that determines a communication route, wherein the route control device includes at least: a communication route calculation unit that calculates a communication route in response to a route switching request; and a forward destination setting instruction unit that outputs forward destination setting information based on the communication route, the signal forwarding devices include at least: a forward destination setting instruction acquisition unit that acquires the forward destination setting information; a forward destination set unit that changes a forward destination based on the forward destination setting information; and a forward unit that outputs input traffic based on the forward destination, and any of the route control device and the signal forwarding devices includes: a traffic monitor unit; a non-signal period estimation unit that estimates a non-signal period in which the traffic does not flow; and a switching timing control unit that controls a switching timing to perform route switching in the non-signal period.

公开(公告)号：US20200177280A1

公开(公告)日：2020-06-04

申请号：US16631513

申请日：2018-07-19

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hirotaka UJIKAWA ,  Noriyuki OOTA ,  Kota ASAKA

IPC: H04B10/27 ,  H04L12/911

Abstract: A virtual subscriber line terminal station device includes a software component including software to be added in accordance with a service requirement; and hardware having general-purpose functions; wherein the hardware includes a communication unit that receives a bandwidth allocation request transmitted by a subscriber line termination device; and the software component includes a bandwidth allocation component. The bandwidth allocation component has an individual unit that, based on an algorithm for allocating bands, computes a bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request; a common unit that, in accordance with the bandwidth allocated by the individual unit, allocates the bandwidth to the subscriber line termination device; and an interface between the individual unit and the common unit. The common unit converts the bandwidth allocation request received by the communication unit to a format that can be used by the individual unit. The individual unit computes the bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request that is converted, by the common unit, to a format that can be used by the individual unit.