Patents by Inventor Kota Asaka

Kota Asaka 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: 20190312661
    Abstract: An optical transceiver includes a wavelength-tunable transmission unit configured to transmit an optical transmission signal, a wavelength-tunable reception unit configured to receive an optical reception signal, a wavelength table configured to store a plurality of combinations of a transmission wavelength and a reception wavelength, an input terminal configured to input a wavelength selection signal, and a control unit configured to select one combination of the transmission wavelength and the reception wavelength from the wavelength table based on the wavelength selection signal, and perform transmission wavelength control for setting the selected transmission wavelength in the wavelength-tunable transmission unit as a wavelength of the optical transmission signal and reception wavelength control for setting the selected reception wavelength in the wavelength-tunable reception unit as a wavelength of the optical reception signal.
    Type: Application
    Filed: June 19, 2017
    Publication date: October 10, 2019
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa TAGUCHI, Kota ASAKA
  • Patent number: 10361807
    Abstract: An OLT configures combinations of wavelength pairs used for upstream and downstream signals, in a wavelength multiplexing optical communication system which performs single-core bidirectional transmission of a plurality of upstream and downstream signals, in such a way that the maximum value of the chromatic dispersion delay amount calculated from each wavelength pair is less than the maximum value of the chromatic dispersion delay amounts calculated when the combinations of wavelength pairs used for upstream and downstream signals are both allocated from the short wave side.
    Type: Grant
    Filed: January 6, 2016
    Date of Patent: July 23, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa Taguchi, Tomoaki Yoshida, Kota Asaka, Shunji Kimura
  • Publication number: 20190123845
    Abstract: An optical transceiver includes: a wavelength-tunable transmitter transmitting an optical transmission signal; a wavelength-tunable receiver receiving an optical reception signal; a wavelength table storing a plurality of wavelengths; an input terminal inputs a wavelength selection signal; and a control unit that identifies one of the optical transmission signal and the optical reception signal as a target based on the wavelength selection signal, selects the wavelength from the wavelength table based on the wavelength selection signal, performs transmission wavelength control in which the selected wavelength is set in the wavelength-tunable transmitter as a wavelength of the optical transmission signal in the case that the optical transmission signal is identified as the target, and performs reception wavelength control in which the selected wavelength is set in the wavelength-tunable receiver as a wavelength of the optical reception signal in the case that the optical reception signal is identified as the t
    Type: Application
    Filed: June 19, 2017
    Publication date: April 25, 2019
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa TAGUCHI, Kota ASAKA
  • Patent number: 10250331
    Abstract: A subscriber device includes a demultiplexer configured to demultiplex input wavelength-multiplexed light into a plurality of light signals for each wavelength, a plurality of light receivers configured to receive each of the plurality of light signals obtained through demultiplexing by the demultiplexer and to convert the light signals into electrical signals, a plurality of limiting amplifiers configured to amplify each of the plurality of electrical signals output from the plurality of light receivers, and a plurality of signal selection units configured to select a plurality of signals to be received from among a plurality of amplified signals output from the plurality of limiting amplifiers.
    Type: Grant
    Filed: May 19, 2016
    Date of Patent: April 2, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa Taguchi, Kota Asaka
  • Patent number: 10230485
    Abstract: In a case where a wavelength to be assigned to a subscriber-side device, to which a downstream wavelength has been assigned, is to be changed from the currently used (Source) downstream wavelength to a different changeover target (Target) downstream wavelength, a downstream wavelength changeover instruction message that indicates the change target wavelength is generated. In a case where a wavelength to be assigned to the subscriber-side device, to which an upstream wavelength has been assigned, is to be changed from the currently used (Source) upstream wavelength to a different changeover target (Target) upstream wavelength, an upstream wavelength changeover instruction message that indicates the change target wavelength is generated. The downstream wavelength changeover instruction message and the upstream wavelength changeover instruction message are respectively independently generated, and only the wavelength for which the wavelength changeover instruction message was generated is changed.
    Type: Grant
    Filed: April 20, 2016
    Date of Patent: March 12, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomoaki Yoshida, Kota Asaka, Shunji Kimura
  • Publication number: 20180351685
    Abstract: An OLT configures combinations of wavelength pairs used for upstream and downstream signals, in a wavelength multiplexing optical communication system which performs single-core bidirectional transmission of a plurality of upstream and downstream signals, in such a way that the maximum value of the chromatic dispersion delay amount calculated from each wavelength pair is less than the maximum value of the chromatic dispersion delay amounts calculated when the combinations of wavelength pairs used for upstream and downstream signals are both allocated from the short wave side.
    Type: Application
    Filed: January 6, 2016
    Publication date: December 6, 2018
    Inventors: Katsuhisa Taguchi, Tomoaki Yoshida, Kota Asaka, Shunji Kimura
  • Publication number: 20180145758
    Abstract: A subscriber device includes a demultiplexer configured to demultiplex input wavelength-multiplexed light into a plurality of light signals for each wavelength, a plurality of light receivers configured to receive each of the plurality of light signals obtained through demultiplexing by the demultiplexer and to convert the light signals into electrical signals, a plurality of limiting amplifiers configured to amplify each of the plurality of electrical signals output from the plurality of light receivers, and a plurality of signal selection units configured to select a plurality of signals to be received from among a plurality of amplified signals output from the plurality of limiting amplifiers.
    Type: Application
    Filed: May 19, 2016
    Publication date: May 24, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa TAGUCHI, Kota ASAKA
  • Publication number: 20180131461
    Abstract: In a case where a wavelength to be assigned to a subscriber-side device, to which a downstream wavelength has been assigned, is to be changed from the currently used (Source) downstream wavelength to a different changeover target (Target) downstream wavelength, a downstream wavelength changeover instruction message that indicates the change target wavelength is generated. In a case where a wavelength to be assigned to the subscriber-side device, to which an upstream wavelength has been assigned, is to be changed from the currently used (Source) upstream wavelength to a different changeover target (Target) upstream wavelength, an upstream wavelength changeover instruction message that indicates the change target wavelength is generated. The downstream wavelength changeover instruction message and the upstream wavelength changeover instruction message are respectively independently generated, and only the wavelength for which the wavelength changeover instruction message was generated is changed.
    Type: Application
    Filed: April 20, 2016
    Publication date: May 10, 2018
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Tomoaki YOSHIDA, Kota ASAKA, Shunji KIMURA
  • Patent number: 9923637
    Abstract: A bias point of an external modulator is set to different values according to on and off of a burst control signal and an optical source is driven continuously in a burst optical signal transmission device. The burst optical signal transmission device avoid generation of transient fluctuation of a wavelength and a light amount at the time of burst signal rising.
    Type: Grant
    Filed: June 24, 2014
    Date of Patent: March 20, 2018
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kota Asaka, Katsuhisa Taguchi, Hirotaka Nakamura
  • Patent number: 9912116
    Abstract: A burst optical signal transmission device which includes a light source for generating and outputting burst signal light, a light source driving circuit for outputting, to the light source, a driving signal for switching between an output time and a stop time of the burst signal light, based on a burst control signal, and a pre-emphasis circuit for outputting a pre-emphasis control signal for superimposing an additional signal for charging a capacitor included in the light source, onto the driving signal, at a timing in the vicinity of the beginning of the burst control signal.
    Type: Grant
    Filed: October 26, 2015
    Date of Patent: March 6, 2018
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Kota Asaka, Katsuhisa Taguchi
  • Publication number: 20170237232
    Abstract: A burst optical signal transmission device which includes a light source for generating and outputting burst signal light, a light source driving circuit for outputting, to the light source, a driving signal for switching between an output time and a stop time of the burst signal light, based on a burst control signal, and a pre-emphasis circuit for outputting a pre-emphasis control signal for superimposing an additional signal for charging a capacitor included in the light source, onto the driving signal, at a timing in the vicinity of the beginning of the burst control signal.
    Type: Application
    Filed: October 26, 2015
    Publication date: August 17, 2017
    Inventors: Kota ASAKA, Katsuhisa TAGUCHI
  • Publication number: 20160127045
    Abstract: A bias point of an external modulator is set to different values according to on and off of a burst control signal and an optical source is driven continuously in a burst optical signal transmission device. The burst optical signal transmission device avoid generation of transient fluctuation of a wavelength and a light amount at the time of burst signal rising.
    Type: Application
    Filed: June 24, 2014
    Publication date: May 5, 2016
    Inventors: Kota ASAKA, Katsuhisa TAGUCHI, Hirotaka NAKAMURA
  • Publication number: 20110170832
    Abstract: An optical transceiver module that is capable of being inserted into and removed from a cage includes a housing that houses a photoelectric conversion element, the housing having a guiding section formed along a front-rear direction, an operating lever that has an operating section and a lever-side contact section, the operating lever being attached to the housing in a rotatable manner about an axis of rotation; and a slider that has a wedge section that engages with a latching section provided to the cage, and a slider-side contact section that comes into contact with the lever-side contact section, the slider being guided in the front-rear direction by the guiding section, the lever-side contact section being located opposite the operating section with respect to the axis of rotation, and as the operating section is pushed rearward, the lever-side contact section pushes the slider-side contact section forward and the slider moves forward to a position where the wedge section is unlatched from the latching s
    Type: Application
    Filed: January 4, 2011
    Publication date: July 14, 2011
    Applicants: Fujikura Ltd., Nippon Telegraph and Telephone Corporation, NTT Electronics Corporation
    Inventors: Sawako Yamai, Susumu Okabe, Tsuyoshi Ito, Kota Asaka, Koji Kitahara, Toshio Ishikawa