Patents by Inventor Hiroki OI

Hiroki OI has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240129034
    Abstract: A forward Raman amplifier includes a plurality of pumping light sources with different wavelengths and the forward Raman amplifier, according to a fiber type or a zero-dispersion wavelength of the fiber, changes the number of pumping light sources to be emitted, changes a power ratio between the plurality of pumping light sources with the different wavelengths or changes wavelength characteristics of a gain, according to a fiber type.
    Type: Application
    Filed: July 12, 2023
    Publication date: April 18, 2024
    Applicant: Fujitsu Limited
    Inventors: Hiroshi NAKAMOTO, GOJI NAKAGAWA, Kentaro KAWANISHI, Hiroki OI, Tomohiro YAMAUCHI, Takafumi TERAHARA, Teppei OHATA
  • Patent number: 11876559
    Abstract: An optical transmission system includes a first optical node, a second optical node, and an optical fiber provided between the first optical node and the second optical node. The optical transmission system further includes: a signal generator provided in the first optical node and configured to generate an optical signal including a plurality of wavelength channels and an empty channel; an optical transmission circuit provided in the first optical node and configured to output the optical signal to the optical fiber; an optical channel monitor provided in the second optical node and configured to measure reception power of each channel in the optical signal received through the optical fiber; and a processor configured to determine a type of the optical fiber based on the reception power of the empty channel, the reception power being measured by the optical channel monitor.
    Type: Grant
    Filed: July 29, 2022
    Date of Patent: January 16, 2024
    Assignee: FUJITSU LIMITED
    Inventors: Goji Nakagawa, Takafumi Terahara, Hiroki Oi
  • Publication number: 20220385364
    Abstract: An optical transmission system includes a first optical node, a second optical node, and an optical fiber provided between the first optical node and the second optical node. The optical transmission system further includes: a signal generator provided in the first optical node and configured to generate an optical signal including a plurality of wavelength channels and an empty channel; an optical transmission circuit provided in the first optical node and configured to output the optical signal to the optical fiber; an optical channel monitor provided in the second optical node and configured to measure reception power of each channel in the optical signal received through the optical fiber; and a processor configured to determine a type of the optical fiber based on the reception power of the empty channel, the reception power being measured by the optical channel monitor.
    Type: Application
    Filed: July 29, 2022
    Publication date: December 1, 2022
    Applicant: FUJITSU LIMITED
    Inventors: GOJI NAKAGAWA, Takafumi Terahara, Hiroki Oi
  • Patent number: 10541749
    Abstract: A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.
    Type: Grant
    Filed: March 19, 2019
    Date of Patent: January 21, 2020
    Assignee: FUJITSU LIMITED
    Inventors: Shigeru Ishii, Hiroki Oi, Takehiro Fujita, Tatsuya Tsuzuki
  • Publication number: 20190312641
    Abstract: A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.
    Type: Application
    Filed: March 19, 2019
    Publication date: October 10, 2019
    Applicant: FUJITSU LIMITED
    Inventors: Shigeru ISHII, Hiroki Oi, Takehiro Fujita, Tatsuya Tsuzuki
  • Patent number: 10256903
    Abstract: A network controller includes: a first acquisition unit configured to acquire, based on a signal quality amount of each of wavelength paths set in a network of an optical wavelength-multiplexed transmission system, a signal quality amount of each of spans in each of the wavelength paths; an arithmetic unit configured to calculate a signal quality amount of each of spans in a wavelength path of an estimation target, based on the signal quality amount acquired by the first acquisition unit; and an estimation unit configured to estimate a signal quality amount of the wavelength path of the estimation target, based on the signal quality amount calculated by the arithmetic unit.
    Type: Grant
    Filed: November 22, 2017
    Date of Patent: April 9, 2019
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Takeshi Hoshida, Hisao Nakashima, Hiroki Oi
  • Patent number: 10020878
    Abstract: An optical signal-to-noise ratio monitor includes: a measuring unit that measures an optical signal-to-noise ratio of a polarization multiplexed optical signal, a polarization state of the polarization multiplexed optical signal changing with respect to time; a selector that selects, from a plurality of optical signal-to-noise ratios measured by the measuring unit at a plurality of measurement points within a designated measurement period, an optical signal-to-noise ratio that is higher than an average of the plurality of optical signal-to-noise ratios; and an output unit that outputs the optical signal-to-noise ratio selected by the selector.
    Type: Grant
    Filed: April 17, 2015
    Date of Patent: July 10, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Hiroki Oi, Satoru Okano, Yoichi Akasaka, Jeng-Yuan Yang
  • Publication number: 20180097562
    Abstract: A network controller includes: a first acquisition unit configured to acquire, based on a signal quality amount of each of wavelength paths set in a network of an optical wavelength-multiplexed transmission system, a signal quality amount of each of spans in each of the wavelength paths; an arithmetic unit configured to calculate a signal quality amount of each of spans in a wavelength path of an estimation target, based on the signal quality amount acquired by the first acquisition unit; and an estimation unit configured to estimate a signal quality amount of the wavelength path of the estimation target, based on the signal quality amount calculated by the arithmetic unit.
    Type: Application
    Filed: November 22, 2017
    Publication date: April 5, 2018
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Takeshi Hoshida, Hisao Nakashima, Hiroki Oi
  • Patent number: 9906296
    Abstract: A network controller includes: a first acquisition unit configured to acquire, based on a signal quality amount of each of wavelength paths set in a network of an optical wavelength-multiplexed transmission system, a signal quality amount of each of spans in each of the wavelength paths; an arithmetic unit configured to calculate a signal quality amount of each of spans in a wavelength path of an estimation target, based on the signal quality amount acquired by the first acquisition unit; and an estimation unit configured to estimate a signal quality amount of the wavelength path of the estimation target, based on the signal quality amount calculated by the arithmetic unit.
    Type: Grant
    Filed: June 3, 2016
    Date of Patent: February 27, 2018
    Assignee: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Takeshi Hoshida, Hisao Nakashima, Hiroki Oi
  • Publication number: 20160373187
    Abstract: A network controller includes: a first acquisition unit configured to acquire, based on a signal quality amount of each of wavelength paths set in a network of an optical wavelength-multiplexed transmission system, a signal quality amount of each of spans in each of the wavelength paths; an arithmetic unit configured to calculate a signal quality amount of each of spans in a wavelength path of an estimation target, based on the signal quality amount acquired by the first acquisition unit; and an estimation unit configured to estimate a signal quality amount of the wavelength path of the estimation target, based on the signal quality amount calculated by the arithmetic unit.
    Type: Application
    Filed: June 3, 2016
    Publication date: December 22, 2016
    Applicant: FUJITSU LIMITED
    Inventors: Shoichiro Oda, Yasuhiko Aoki, Takeshi Hoshida, Hisao Nakashima, Hiroki Oi
  • Publication number: 20160308611
    Abstract: An optical signal-to-noise ratio monitor includes: a measuring unit that measures an optical signal-to-noise ratio of a polarization multiplexed optical signal, a polarization state of the polarization multiplexed optical signal changing with respect to time; a selector that selects, from a plurality of optical signal-to-noise ratios measured by the measuring unit at a plurality of measurement points within a designated measurement period, an optical signal-to-noise ratio that is higher than an average of the plurality of optical signal-to-noise ratios; and an output unit that outputs the optical signal-to-noise ratio selected by the selector.
    Type: Application
    Filed: April 17, 2015
    Publication date: October 20, 2016
    Applicant: Fujitsu Limited
    Inventors: Shoichiro ODA, Yasuhiko AOKI, Hiroki Oi, Satoru OKANO, Yoichi AKASAKA, Jeng-Yuan YANG
  • Patent number: 9444572
    Abstract: A transmission device includes: optical transmitters configured to transmit optical signals of different wavelengths; optical couplers configured to multiplexing the optical signals transmitted from the optical transmitters; and a wavelength selective switch configured to multiplex multiplexed optical signals obtained by multiplexing by the couplers, wherein optical signals, a wavelength interval between which is less than a predetermined value, are transmitted to separate optical couplers of the optical couplers, among the optical signals.
    Type: Grant
    Filed: September 23, 2013
    Date of Patent: September 13, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Tomohiro Kaneoka, Norifumi Shukunami, Hiroki Oi
  • Patent number: 9432113
    Abstract: An optical transmission device including a wavelength selective switch including plural output ports, an optical intensity monitoring device that receives each optical signal output from the plural output ports of the wavelength selective switch and monitors the optical intensity of the optical signals, and a controller that controls optical intensity of the optical signals from the plural output ports of the wavelength selective switch based on the optical intensities monitored by the optical intensity monitoring device.
    Type: Grant
    Filed: December 10, 2014
    Date of Patent: August 30, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Hiroki Oi, Kosuke Komaki
  • Patent number: 9071379
    Abstract: An optical branching and insertion device includes an optical splitter that branches an input optical signal, and outputs the branched optical signal from a first output port and a second output port; a wavelength selective switch that allows passage of an optical signal of a predetermined wavelength from among optical signals input to a first input port from the first output port, and outputs the optical signal of the predetermined wavelength and an optical signal inputted from a second input port; and a processor that executes a process to expand a band through which the optical signal of the predetermined wavelength is allowed to pass, the process being executed when a channel allocated to a wavelength of the optical signal inputted from the second input port and a channel allocated to the predetermined wavelength are not adjacent.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: June 30, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Hiroki Oi, Takafumi Terahara
  • Publication number: 20150098696
    Abstract: An optical transmission device including a wavelength selective switch including plural output ports, an optical intensity monitoring device that receives each optical signal output from the plural output ports of the wavelength selective switch and monitors the optical intensity of the optical signals, and a controller that controls optical intensity of the optical signals from the plural output ports of the wavelength selective switch based on the optical intensities monitored by the optical intensity monitoring device.
    Type: Application
    Filed: December 10, 2014
    Publication date: April 9, 2015
    Applicant: FUJITSU LIMITED
    Inventors: Hiroki OI, Kosuke KOMAKI
  • Publication number: 20140126903
    Abstract: A transmission device includes: optical transmitters configured to transmit optical signals of different wavelengths; optical couplers configured to multiplexing the optical signals transmitted from the optical transmitters; and a wavelength selective switch configured to multiplex multiplexed optical signals obtained by multiplexing by the couplers, wherein optical signals, a wavelength interval between which is less than a predetermined value, are transmitted to separate optical couplers of the optical couplers, among the optical signals.
    Type: Application
    Filed: September 23, 2013
    Publication date: May 8, 2014
    Applicant: Fujitsu Limited
    Inventors: Tomohiro KANEOKA, Norifumi SHUKUNAMI, Hiroki OI
  • Publication number: 20140010535
    Abstract: An optical branching and insertion device includes an optical splitter that branches an input optical signal, and outputs the branched optical signal from a first output port and a second output port; a wavelength selective switch that allows passage of an optical signal of a predetermined wavelength from among optical signals input to a first input port from the first output port, and outputs the optical signal of the predetermined wavelength and an optical signal inputted from a second input port; and a processor that executes a process to expand a band through which the optical signal of the predetermined wavelength is allowed to pass, the process being executed when a channel allocated to a wavelength of the optical signal inputted from the second input port and a channel allocated to the predetermined wavelength are not adjacent.
    Type: Application
    Filed: June 4, 2013
    Publication date: January 9, 2014
    Inventors: Hiroki OI, Takafumi Terahara