公开(公告)号：US20240118127A1

公开(公告)日：2024-04-11

申请号：US18275848

申请日：2021-02-26

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Daisuke IIDA ,  Yoshitaka ENOMOTO ,  Chihiro KITO ,  Tatsuya OKAMOTO ,  Yusuke KOSHIKIYA ,  Yoshifumi WAKISAKA ,  Nazuki HONDA

IPC: G01H9/00

CPC classification number: G01H9/004

Abstract: The present disclosure is an optical line test system that detects a distribution of loss points of an optical line in a longitudinal direction, using a coherent light measurement device, applies vibration to facility disposed on a path of the optical line, detects a vibration point of the optical line in a longitudinal direction upon applying the vibration, using the coherent light measurement device, and identifies the loss point based on correspondence between the detected loss point and vibration point.

公开(公告)号：US20240427139A1

公开(公告)日：2024-12-26

申请号：US18701322

申请日：2021-10-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Keisuke MURAKAMI ,  Hideaki MYANISHI ,  Chihiro KITO ,  Taku YAMANE

IPC: G02B27/00

Abstract: In order to achieve the above object, a loop wiring designing apparatus according to the present disclosure creates loops in which optical fibers on a map are connected in a loop shape using input facility information and map information, deletes at least some of overlapping loops, having a certain amount of overlapping loop area or more surrounded by the loops on the map, of the created loops to cancel overlapping loops, on an occasion where a loop group, after cancelation of the overlapping loops includes a loop outside a demand number range, having an assumed demand number arising both inside and outside the loop being out of a demand number range set at discretion, repeats deletion of the loop out of the demand number range and re-cancelation of the overlapping loops, and designs a loop group including only loops in which the demand number falls within the demand number range as a selected loop group.

公开(公告)号：US20250028078A1

公开(公告)日：2025-01-23

申请号：US18709686

申请日：2021-12-02

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Chihiro KITO ,  Yusuke KOSHIKIYA ,  Daisuke IIDA

IPC: G01W1/14

Abstract: Objects of the present invention are to provide a snow accumulation estimating system and a method for estimating a snow accumulation which enable a snow accumulation to be remotely measured accurately and economically.
A snow accumulation estimating system 301 according to the present invention includes: an optical fiber 50 that receives vibration from a random point on snow; a vibration measuring instrument 11 that measures the vibration received by the optical fiber 50 as a distribution in a longitudinal direction of the optical fiber 50; and an analysis processing unit 12 that has, as accumulated data, a relationship between a snow accumulation and the vibration received by the optical fiber 50, compares the distribution measured as measurement data by the vibration measuring instrument 11 with the accumulated data, and estimates a snow accumulation at the random point.

公开(公告)号：US20240310192A1

公开(公告)日：2024-09-19

申请号：US18576031

申请日：2021-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Chihiro KITO

IPC: G01D5/353

CPC classification number: G01D5/35364

Abstract: In the present disclosure, a direction of a change ΔBFS in a Brillouin frequency shift amount of an optical fiber to be measured M from a steady state or a non-application state to the non-steady state or the application state is detected as is determined as one of a positive direction and a negative direction based on first beat frequencies ΔR1 and ΔR1′ and second beat frequencies ΔR2 and ΔR2′ between Brillouin frequency shift amounts BFSM and BFSM′ of the optical fiber to be measured M and constant Brillouin frequency shift amounts BFSR1 and BFSR2 of a first reference optical fiber 7 and a second reference optical fiber 9 in the steady state of temperature or the non-application state of strain or vibration and in the non-steady state of temperature or the application state of strain or vibration.

公开(公告)号：US20240259099A1

公开(公告)日：2024-08-01

申请号：US18563451

申请日：2021-05-31

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Taku YAMANE ,  Chihiro KITO ,  Shingo ONO

IPC: H04B10/275

CPC classification number: H04B10/275

Abstract: The present disclosure provides an optical access network and a method for designing the same, in which a plurality of optical cable loops, in which optical cables are connected in a loop shape, are disposed between a communication station building and an optical termination position, and the optical cable loops are connected to each other.

公开(公告)号：US20240063911A1

公开(公告)日：2024-02-22

申请号：US18269885

申请日：2021-01-27

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shingo ONO ,  Chihiro KITO

IPC: H04B10/275 ,  H04Q11/00

CPC classification number: H04B10/2755 ,  H04Q11/0005 ,  H04Q2011/0041

Abstract: An object of the present invention is to provide an optical access network that has high reliability for supporting information communication services and efficiently responds to difficult-to-predict optical fiber demand.
An optical access network configuration according to the present invention includes an optical fiber cable 11 that is looped to connect a wiring section 25 and an exchange office 10 together (hereinafter, an upper loop), an optical fiber cable 21 that is looped and laid in each wiring section 25 (hereinafter, a lower loop), and an optical fiber switching function unit 31 installed at a connection point 30 between the upper loop 11 and the lower loop 21. The optical fiber switching function unit 31 is a wiring board or an optical switch which can be switched by connector connection. The wiring board or the optical switch may be remotely controllable.

公开(公告)号：US20230236044A1

公开(公告)日：2023-07-27

申请号：US17923263

申请日：2020-05-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsushi NAKAMURA ,  Chihiro KITO ,  Daisuke IIDA ,  Junichi KAWATAKA ,  Hiroyuki OSHIDA

IPC: G01D5/353

CPC classification number: G01D5/35364

Abstract: An object of the present invention is to provide a Brillouin optical sensing device and an optical sensing method capable of reducing introduction costs. The Brillouin optical sensing device according to the present invention includes: a sensing fiber 90 in which a plurality of optical fibers having Brillouin frequency shift characteristics different from each other are arranged in parallel; an optical measuring instrument 11 that launches an optical pulse into at least two of the optical fibers of the sensing fiber 90 to generate Brillouin scattering lights and measures a beat frequency of a beat signal between the Brillouin scattering lights at any position of the sensing fiber 90; and an arithmetic processing unit 12 that acquires a physical quantity of the sensing fiber 90 at said any position based on the beat frequency acquired by the optical measuring instrument 11.