公开(公告)号：US20230082934A1

公开(公告)日：2023-03-16

申请号：US17798068

申请日：2020-02-12

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kazutaka HARA ,  Yasutaka KIMURA ,  Atsuko KAWAKITA

IPC: H04B10/61 ,  H04B10/25

Abstract: In order to solve the problems described above, an object of the present invention is to provide an optical communication system and a control method that automatically adjust a branching ratio of an optical splitter in accordance with a connection of a new ONU. An optical communication system according to the present invention causes an operation system or a DBA (Dynamic Bandwidth Allocation) function and a determining unit of a branching ratio of an optical splitter to cooperate with each other, adjusts the branching ratio so as to enable ranging with an active ONU, and takes into consideration an initial connection sequence through which an ONU is newly connected.

公开(公告)号：US20220291118A1

公开(公告)日：2022-09-15

申请号：US17638122

申请日：2019-08-27

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Tomohiro TANIGUCHI ,  Kazutaka HARA ,  Atsuko KAWAKITA

IPC: G01N21/21

Abstract: An objective of the present invention is to provide an optical measurement device capable of performing remote optical measurement. An optical measurement device may include a light source that generates irradiation light with a beam shape, a beam control unit configured to control an irradiation direction of the irradiation light L1, a condensing unit configured to condense returned light generated by irradiating a part of a measurement target with the irradiation light, and a detection unit configured to detect information regarding the measurement target included in the returned light condensed by the condensing unit. The beam control unit can control the irradiation direction of the irradiation light for measurement to any direction, and thus the condensing unit can efficiently receive the faint returned light from the measurement target.

公开(公告)号：US20220166532A1

公开(公告)日：2022-05-26

申请号：US17440410

申请日：2020-03-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsuko KAWAKITA ,  Kazutaka HARA ,  Yasutaka KIMURA ,  Kenji HORIKAWA ,  Hiroyuki FURUKAWA

IPC: H04J14/02 ,  G02B6/287 ,  H04B10/272

Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

公开(公告)号：US20210194589A1

公开(公告)日：2021-06-24

申请号：US17271222

申请日：2019-08-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsuko KAWAKITA ,  Kazutaka HARA ,  Hiroyuki FURUKAWA ,  Yasutaka KIMURA ,  Kenji HORIKAWA

IPC: H04B10/272 ,  H04L12/44 ,  G02B6/27

Abstract: To provide an optical communication system and an optical communication method able to achieve a high reliable access network capable of long haul distance transmission considering the optical energy efficiency even if the user distribution is biased. An uneven branch optical splitter included in an optical communication system according to the present invention can output the optical intensities different for each output port by adjusting the branching configuration and the branching ratio. For example, a reach transmission distance of the farmost user can be extended or the number of connectible users can be increased by adjusting the branching configuration of the uneven branch optical splitter or the branching ratios such that the near minimum reception sensitivity is given for the ONU installed near the telecommunications carrier.