Patents by Inventor Hidehiko Takara

Hidehiko Takara 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).

  • Patent number: 10686520
    Abstract: A transmission quality estimation system includes, three or more nodes and a transmission quality estimation device configured to estimate, transmission quality. A multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes. A node of the nodes includes a core connection unit configured to drop, add or relay light transmitted from, to or to each of to the plurality of cores of the multi-core fiber. The transmission quality estimation device includes an estimation unit configured to estimate transmission quality between the nodes on the basis of a transmission quality measurement light dropped by the core connection unit.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: June 16, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Patent number: 10637568
    Abstract: A transmission quality estimation system includes, three or more nodes and a transmission quality estimation device configured to estimate, transmission quality. A multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes. A node of the nodes includes a core connection unit configured to drop, add or relay light transmitted from, to or to each of to the plurality of cores of the multi-core fiber. The transmission quality estimation device includes an estimation unit configured to estimate transmission quality between the nodes on the basis of a transmission quality measurement light dropped by the core connection unit.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: April 28, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Patent number: 10615868
    Abstract: A communication system which includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes; a detection signal output unit configured to output a fault detection signal transmitted by the core provided in the multi-core fiber configured to connect together the nodes; and a fault detection unit configured to determine whether a fault has occurred between the nodes on the basis of a detection result of the fault detection signal.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: April 7, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Patent number: 10527781
    Abstract: A communication system includes three or more nodes and a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of the connection between the nodes is provided. One node of the nodes is connected to the multi-core fiber and includes a connector configured to add and drop a signal to and from an allocated core exclusively allocated from among the cores as a communication path between the one node and another node of the nodes and/or configured to relay a signal transmitted through another core of the cores allocated for communication between other nodes in the multi-core fiber connected to the one node, and a relative positional relationship between a connection position of the allocated core in which a signal is added or dropped in the connector and a connection position of another core in which a signal is relayed in the connector is the same for all of the nodes connected to the multi-core fiber.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: January 7, 2020
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Patent number: 10511381
    Abstract: A communication system includes three or more nodes, and a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes, wherein each of nodes includes: a fault information transmitting device configured to transmit fault information indicating that a fault has occurred in a communication path between one node and another node of the nodes when it is detected that it is not possible to perform communication between the one node and the another node; and a fault location specifying device configured to specify a section between nodes in which a fault has occurred on the basis of the fault information received from the fault information transmitting device provided in each of the nodes.
    Type: Grant
    Filed: November 22, 2016
    Date of Patent: December 17, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya Oda, Tetsuro Inui, Akira Hirano, Wataru Imajuku, Shoukei Kobayashi, Takafumi Tanaka, Yutaka Miyamoto, Hidehiko Takara
  • Publication number: 20180375579
    Abstract: A communication system includes three or more nodes and a multi-core fiber having a plurality of cores and being used in at least a partial segment of the connection between the nodes. One node of the nodes is connected to the multi-core fiber and includes a connector configured to add and drop a signal to and from an allocated core exclusively allocated for communication between the one node and another node of the nodes and/or configured to relay a signal transmitted through another core allocated to communication between the other nodes in multi-core fibers connected to the one node.
    Type: Application
    Filed: November 22, 2016
    Publication date: December 27, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180359024
    Abstract: A communication system which includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes; a detection signal output unit configured to output a fault detection signal transmitted by the core provided in the multi-core fiber configured to connect together the nodes; and a fault detection unit configured to determine whether a fault has occurred between the nodes on the basis of a detection result of the fault detection signal.
    Type: Application
    Filed: November 22, 2016
    Publication date: December 13, 2018
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180358773
    Abstract: An optical amplification system includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of the connection between the nodes; an amplification light input unit configured to input amplification light to a core of the plurality of cores of the multi-core fiber; an amplification unit configured to amplify communication light transmitted through at least one core of the plurality of cores of the multi-core fiber using the amplification light, the amplification unit being provided in the nodes or between the nodes; and an amplification light coupling unit configured to couple the amplification light input by the amplification light input unit to the amplification unit.
    Type: Application
    Filed: November 22, 2016
    Publication date: December 13, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180351639
    Abstract: A communication system includes three or more nodes, and a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes, wherein each of nodes includes: a fault information transmitting device configured to transmit fault information indicating that a fault has occurred in a communication path between one node and another node of the nodes when it is detected that it is not possible to perform communication between the one node and the another node; and a fault location specifying device configured to specify a section between nodes in which a fault has occurred on the basis of the fault information received from the fault information transmitting device provided in each of the nodes
    Type: Application
    Filed: November 22, 2016
    Publication date: December 6, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180343067
    Abstract: A node included in an optical power supply system which includes three or more nodes and a multi-core fiber having a plurality of cores, the plurality of cores being used in at least a partial segment of the connection between the nodes includes: a power supply light dropping unit configured to drop a portion or all of a power supply light from one core of the plurality of cores of the multi-core fiber; a photoelectric conversion unit configured to convert the portion or all of the power supply light dropped by the power supply light dropping unit to an electrical signal; and a power supply target facility configured to operate with the electrical signal converted by the photoelectric conversion unit.
    Type: Application
    Filed: November 22, 2016
    Publication date: November 29, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180341060
    Abstract: A communication system includes three or more nodes and a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of the connection between the nodes is provided. One node of the nodes is connected to the multi-core fiber and includes a connector configured to add and drop a signal to and from an allocated core exclusively allocated from among the cores as a communication path between the one node and another node of the nodes and/or configured to relay a signal transmitted through another core of the cores allocated for communication between other nodes in the multi-core fiber connected to the one node, and a relative positional relationship between a connection position of the allocated core in which a signal is added or dropped in the connector and a connection position of another core in which a signal is relayed in the connector is the same for all of the nodes connected to the multi-core fiber.
    Type: Application
    Filed: November 22, 2016
    Publication date: November 29, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Publication number: 20180337726
    Abstract: A transmission quality estimation system includes, three or more nodes and a transmission quality estimation device configured to estimate, transmission quality. A multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes. A node of the nodes includes a core connection unit configured to drop, add or relay light transmitted from, to or to each of to the plurality of cores of the multi-core fiber. The transmission quality estimation device includes an estimation unit configured to estimate transmission quality between the nodes on the basis of a transmission quality measurement light dropped by the core connection unit.
    Type: Application
    Filed: November 22, 2016
    Publication date: November 22, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takuya ODA, Tetsuro INUI, Akira HIRANO, Wataru IMAJUKU, Shoukei KOBAYASHI, Takafumi TANAKA, Yutaka MIYAMOTO, Hidehiko TAKARA
  • Patent number: 9762982
    Abstract: There is provided a multi-flow optical transceiver that includes (a) a plurality of wavelength-tunable light sources, (b) a plurality of optical modulation units which modulates light with an input signal, (c) an optical multiplexing/demultiplexing switch which couples light from at least one of the wavelength-tunable light sources to at least one of the optical modulation units with any power, (d) an optical coupling unit which couples a plurality of lights, modulated by a plurality of the optical modulation units, to at least one waveguide, (e) at least one multiple carrier generating unit which generates multiple carries, arranged at equal frequency intervals, from light of the wavelength-tunable light source, and (f) a wavelength separation unit which branches the multiple carriers from the multiple carrier generating unit for each wavelength.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: September 12, 2017
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kazushige Yonenaga, Hidehiko Takara, Masahiko Jinno, Kohki Shibahara, Takashi Goh
  • Patent number: 9479282
    Abstract: An optical communication apparatus, in the sending side, distributes client signals according to destinations and a communication capacity of each destination, electrical-to-optical converts the distributed signals to optical signals having different center frequencies, and multiplexes the optical signals to output, and in the receiving side, the optical communication apparatus divides the wavelength division multiplexed signal to each wavelength (for each sending source), optical-to-electrical converts the divided optical signals to electrical signals, and multiplexes the electrical signals to output. An add/drop port of an optical route switching apparatus includes an input/output port to the optical communication apparatus, and an optical frequency bandwidth is variable according to an optical spectrum width of the optical signal. A network is constructed by using the optical communication apparatus and the optical route switching apparatus.
    Type: Grant
    Filed: April 26, 2012
    Date of Patent: October 25, 2016
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Masahiko Jinno, Hidehiko Takara, Kazushige Yonenaga, Akira Hirano, Yoshiaki Sone
  • Publication number: 20160205451
    Abstract: There is provided a multi-flow optical transceiver that includes (a) a plurality of wavelength-tunable light sources, (b) a plurality of optical modulation units which modulates light with an input signal, (c) an optical multiplexing/demultiplexing switch which couples light from at least one of the wavelength-tunable light sources to at least one of the optical modulation units with any power, (d) an optical coupling unit which couples a plurality of lights, modulated by a plurality of the optical modulation units, to at least one waveguide, (e) at least one multiple carrier generating unit which generates multiple carries, arranged at equal frequency intervals, from light of the wavelength-tunable light source, and (f) a wavelength separation unit which branches the multiple carriers from the multiple carrier generating unit for each wavelength.
    Type: Application
    Filed: March 24, 2016
    Publication date: July 14, 2016
    Inventors: Kazushige YONENAGA, Hidehiko TAKARA, Masahiko JINNO, Kohki SHIBAHARA, Takashi GOH
  • Patent number: 9326049
    Abstract: A multi-flow optical transceiver provided with a plurality of wavelength-tunable light sources, a plurality of optical modulation units which modulates light with an input signal, an optical multiplexing/demultiplexing switch which couples light from at least one of the wavelength-tunable light sources to at least one of the optical modulation units with any power, and an optical coupling unit which couples a plurality of lights, modulated by a plurality of the optical modulation units, to at least one waveguide.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: April 26, 2016
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kazushige Yonenaga, Hidehiko Takara, Masahiko Jinno, Kohki Shibahara, Takashi Goh
  • Patent number: 9065243
    Abstract: The phase sensitive amplifier according to the present invention is a phase sensitive amplifier that uses the optical mixing using a nonlinear optical effect to amplify the signal light. The phase sensitive amplifier according to the present invention includes: the first second-order nonlinear optical element; and the second second-order nonlinear optical element. The first second-order nonlinear optical element causes the fundamental wave light to generate second harmonic light used as pump light and separates only the second harmonic light. The second second-order nonlinear optical element includes a multiplexer to multiplex the signal light with the second harmonic light and spectrally separates only the amplified signal light. The multiplexed signal light and second harmonic light are used subjected to parametric amplification.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: June 23, 2015
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Masaki Asobe, Takeshi Umeki, Kouji Enbutsu, Akio Tokura, Yutaka Miyamoto, Hidehiko Takara, Hirokazu Takenouchi, Isao Tomita
  • Patent number: 8964581
    Abstract: A bandwidth variable communication method is provided that enables effective use of frequency bandwidths in which the bit rate is constant in every optical path. The bandwidth variable communication method includes, when a network management apparatus sets or changes an optical path that passes through plural communication apparatuses, measuring or obtaining an optical signal quality deterioration amount in a route of the optical path; selecting a modulation format in which a spectrum bandwidth is the narrowest from among modulation formats by which transmission is available on conditions of the optical signal quality deterioration amount and a desired bit rate B (bit/s); and exchanging control information between the network management apparatus and a control unit of each communication apparatus on the optical path route. A bandwidth variable communication apparatus receives the control information, and changes a passband based on the received control information.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: February 24, 2015
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Hidehiko Takara, Masahiko Jinno, Atsushi Watanabe, Kozicki Bartlomiej, Yoshiaki Sone, Akira Hirano, Takafumi Tanaka
  • Publication number: 20150036210
    Abstract: The phase sensitive amplifier according to the present invention is a phase sensitive amplifier that uses the optical mixing using a nonlinear optical effect to amplify the signal light. The phase sensitive amplifier according to the present invention includes: the first second-order nonlinear optical element; and the second second-order nonlinear optical element. The first second-order nonlinear optical element causes the fundamental wave light to generate second harmonic light used as pump light and separates only the second harmonic light. The second second-order nonlinear optical element includes a multiplexer to multiplex the signal light with the second harmonic light and spectrally separates only the amplified signal light. The multiplexed signal light and second harmonic light are used subjected to parametric amplification.
    Type: Application
    Filed: January 20, 2012
    Publication date: February 5, 2015
    Inventors: Masaki Asobe, Takeshi Umeki, Kouji Enbutsu, Akio Tokura, Yutaka Miyamoto, Hidehiko Takara, Hirokazu Takenouchi, Isao Tomita
  • Publication number: 20140270776
    Abstract: An optical communication apparatus, in the sending side, distributes client signals according to destinations and a communication capacity of each destination, electrical-to-optical converts the distributed signals to optical signals having different center frequencies, and multiplexes the optical signals to output, and in the receiving side, the optical communication apparatus divides the wavelength division multiplexed signal to each wavelength (for each sending source), optical-to-electrical converts the divided optical signals to electrical signals, and multiplexes the electrical signals to output. An add/drop port of an optical route switching apparatus includes an input/output port to the optical communication apparatus, and an optical frequency bandwidth is variable according to an optical spectrum width of the optical signal. A network is constructed by using the optical communication apparatus and the optical route switching apparatus.
    Type: Application
    Filed: April 26, 2012
    Publication date: September 18, 2014
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Masahiko Jinno, Hidehiko Takara, Kazushige Yonenaga, Akira Hirano, Yoshiaki Sone