Patents by Inventor Junichi Kani

Junichi Kani 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: 20220021617
    Abstract: A communication system includes a subscriber network unit and a communication device provided in an accommodating station. The subscriber network unit includes an acquisition unit that acquires uplink data from one or more lower-layer devices. The communication device includes: a data processing unit that acquires the uplink data from the subscriber network unit using a band of uplink communication and executes data processing on the acquired uplink data; a policy determination unit that determines a policy of band allocation of the uplink communication on the basis of the result of the data processing; and an allocation control unit that allocates the band of the uplink communication to the subscriber network unit on the basis of the policy.
    Type: Application
    Filed: December 4, 2019
    Publication date: January 20, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Yumiko SENOO, Takahiro SUZUKI, Junichi KANI, Hirotaka UJIKAWA
  • Publication number: 20210399869
    Abstract: A reception apparatus includes a detection unit that detects occurrence of a phase slip in phase estimation values of time-series received symbol data, and determines an inclination of the phase slip, a delay processing unit that generates first received signal data obtained by delaying received signal data obtained from the time-series received symbol data by one symbol time interval, a phase shift unit that generates second received signal data by performing phase shift according to the inclination, only in a period in which one symbol time interval elapses, on only the received signal data of a symbol time at which the occurrence of the phase slip is detected among pieces of the received signal data, and a remainder processing unit that derives a remainder of a difference between the second received signal data and the first received signal data.
    Type: Application
    Filed: October 9, 2019
    Publication date: December 23, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Sang-Yuep KIM, Takahiro SUZUKI, Junichi KANI
  • Publication number: 20210392064
    Abstract: Provided is a communication device including: a transmission timing calculation unit configured to calculate a transmission timing of a first frame using the number of transmitted bits from a predetermined timing to transmission of the first frame and a throughput; a transmission unit configured to transmit the first frame to an external device at the transmission timing; a reception unit configured to receive a second frame from the external device in response to the first frame; a reception timing calculation unit configured to calculate a reception timing of the second frame using the number of received bits from a predetermined timing to reception of the second frame by the reception unit and a throughput; and a round trip time calculation unit configured to calculate a round trip time using a processing time required by the external device from the reception of the first frame to the transmission of the second frame, the transmission timing, and the reception timing.
    Type: Application
    Filed: October 2, 2019
    Publication date: December 16, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takahiro SUZUKI, Sang-Yuep KIM, Junichi KANI
  • Publication number: 20210336706
    Abstract: An ADC (12) in an optical receiver (1) generates a sample signal composed of time series samples by oversampling a received signal that is an electrical signal converted from an optical signal by a light receiving unit (11). A symbol timing detection unit (132) of a DSP unit (13) detects a symbol timing in the sample signal. When it is determined that a symbol timing is appearing at a longer interval than a predetermined interval based on this detection result, a symbol timing adjusting unit (133) skips one or more samples included in the sample signal to read out samples at the predetermined interval, while when it is determined that the symbol timing is appearing at a shorter interval than the predetermined interval, the symbol timing adjusting unit inserts the same samples as one or more samples included in the sample signal immediately after the one or more samples to read out the samples at the predetermined interval.
    Type: Application
    Filed: August 27, 2019
    Publication date: October 28, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Noriko IIYAMA, Masamichi FUJIWARA, Junichi KANI
  • Publication number: 20210258075
    Abstract: A signal processing device included in an optical reception device configured to receive a burst optical signal transmitted by one of a plurality of optical transmission devices, includes a symbol timing detecting unit configured to detect a symbol timing based on sample signals obtained by oversampling the burst optical signal converted into an electric signal with a sampling rate higher than a symbol rate, an adaptive equalization filter unit configured to perform an equalization process on the sample signals, and a timing matching unit configured to match timing such that, when the adaptive equalization filter unit takes in the sample signals, one of the taken-in sample signals corresponding to the symbol timing is given to a tap of which a tap coefficient has a maximum value among taps included in the adaptive equalization filter unit.
    Type: Application
    Filed: June 5, 2019
    Publication date: August 19, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Noriko IIYAMA, Masamichi FUJIWARA, Junichi KANI
  • Publication number: 20210117178
    Abstract: A communication apparatus includes: a memory that stores, first data on firmware before update, second data on firmware after the update, and a table in which the first data or the second data is associated with an address where the first data or the second data is positioned; and a processor that executes processing based on the first data or the second data positioned at the address defined in the table.
    Type: Application
    Filed: April 8, 2019
    Publication date: April 22, 2021
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Takumi HARADA, Manabu YOSHINO, Junichi KANI
  • Patent number: 8340520
    Abstract: ONU 2A for P-P includes a signal-type discriminating unit 22A that discriminates whether a type of a downstream signal transmitted from OLT is for the P-P or not, and outputs an enable/disable control signal that controls an optical transmitter to an enable state or a disable state, and a control unit 21 that controls the optical transmitter to the enable state or the disable state according to the enable/disable control signal, wherein the signal-type discriminating unit 22A outputs to the control unit 21 a disable control signal that controls the optical transmitter to the disable state under an initial state before the type of the downstream signal is discriminated, and outputs to the control unit 21 an enable control signal that controls the optical transmitter to the enable state after the downstream signal is discriminated to be for the P-P.
    Type: Grant
    Filed: September 18, 2008
    Date of Patent: December 25, 2012
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Junichi Kani, Yukihiro Fujimoto, Ryogo Kubo, Mitsumasa Okada
  • Publication number: 20100239247
    Abstract: ONU 2A for P-P includes a signal-type discriminating unit 22A that discriminates whether a type of a downstream signal transmitted from OLT is for the P-P or not, and outputs an enable/disable control signal that controls an optical transmitter to an enable state or a disable state, and a control unit 21 that controls the optical transmitter to the enable state or the disable state according to the enable/disable control signal, wherein the signal-type discriminating unit 22A outputs to the control unit 21 a disable control signal that controls the optical transmitter to the disable state under an initial state before the type of the downstream signal is discriminated, and outputs to the control unit 21 an enable control signal that controls the optical transmitter to the enable state after the downstream signal is discriminated to be for the P-P.
    Type: Application
    Filed: September 18, 2008
    Publication date: September 23, 2010
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Junichi Kani, Yukihiro Fujimoto, Ryogo Kubo, Mitsumasa Okada
  • Patent number: 7555215
    Abstract: A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths ?d1 to ?dn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths ?d1+?? to ?dn+??, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths ?u1 to ?un or wavelengths ?u1+?? to ?un+??, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: June 30, 2009
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Hirotaka Nakamura, Junichi Kani, Hiroo Suzuki, Mitsuhiro Teshima, Ukyo Yamaguchi, Hidetaka Onishi, Katsumi Iwatsuki
  • Patent number: 7474460
    Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays from end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: January 6, 2009
    Assignee: Nippon Telegraph and Telephone Corporation.
    Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
  • Patent number: 7336414
    Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: February 26, 2008
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
  • Publication number: 20070127113
    Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays from end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.
    Type: Application
    Filed: February 13, 2007
    Publication date: June 7, 2007
    Applicant: Nippon Telegraph and Telephone Corporation
    Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
  • Patent number: 7068412
    Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.
    Type: Grant
    Filed: April 16, 2004
    Date of Patent: June 27, 2006
    Assignee: Nippon Telegraph and Telephone Corp.
    Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
  • Publication number: 20060062576
    Abstract: A dual structure for a multiplexing section extended to an OSU is obtained without adding a dynamic function, such as an optical switch, to a W-MULDEM. The W-MULDEM of an optical wavelength division multiplexing access system divides, among ports corresponding to the individual ONUs, downstream optical signals having wavelengths ?d1 to ?dn, which are received along a current-use optical fiber, or downstream optical signals having wavelengths ?d1+?? to ?dn+??, which are received along a redundant optical fiber. The W-MULDEM also multiplexes, for the port that corresponds to the current-use optical fiber or the redundant optical fiber, upstream optical signals having wavelengths ?u1 to ?un or wavelengths ?u1+?? to ?un+??, which are received along optical fibers corresponding to the ONUs. A wavelength difference between the downstream optical signal and the upstream optical signal that are consonant with each ONU is defined as an integer times the FSR of an AWG.
    Type: Application
    Filed: May 28, 2004
    Publication date: March 23, 2006
    Inventors: Hirotaka Nakamura, Junichi Kani, Hiroo Suzuki, Mitsuhiro Teshima, Ukyo Yamaguchi, Hidetaka Onishi, Katsumi Iwatsuki
  • Publication number: 20060024066
    Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.
    Type: Application
    Filed: June 16, 2004
    Publication date: February 2, 2006
    Inventors: Masamichi Fujiwara, Junichi Kani, Koji Akimoto, Katsumi Iwatsuki
  • Patent number: 6924924
    Abstract: A multi-wavelength generating apparatus generates a wavelength division multiplexing (WDM) signal by modulating light with a single central frequency and with an electric signal having a particular pulse repetition frequency. The resulting optical spectrum configuration is controllable so that a Relative Intensity Noise (RIN) or Signal to Noise Ratio (SNR) requirement may be achieved. A modulated or pulsed light source is used to obtain a discrete spectrum with particular mode spacing, which is then modulated to permit dynamic power control for specific modes of the discrete spectrum.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: August 2, 2005
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
  • Publication number: 20050008373
    Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.
    Type: Application
    Filed: April 16, 2004
    Publication date: January 13, 2005
    Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
  • Patent number: 6831774
    Abstract: Amulti-wavelength generating apparatus generates a wavelength division multiplexing (WDM) signal by modulating light with a single central frequency and an electric signal having a particular pulse repetition frequency. The resulting optical spectrum configuration is conntrollable so that a Relative Intensity Noise (RIN) or Signal to Noise Ratio (SNR) requirement may be achieved. A modulated or pulsed light source in used to obtain a descrete spectrum with particular mode spacing, which is then modulated to permit dynamic power control for specific modes of the discrete spectrum.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: December 14, 2004
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
  • Publication number: 20040100682
    Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.
    Type: Application
    Filed: September 4, 2003
    Publication date: May 27, 2004
    Applicants: Nippon Telegraph and Telephone Corp., International Rectifier Corporation
    Inventors: Masamichi Fujiwara, Katsuhiro Araya, Mitsuhiro Teshima, Junichi Kani, Kenichi Suzuki
  • Patent number: 6583924
    Abstract: In the optical amplifier an optical divider based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter divides input signal light according to wavelengths, and amplifying sections disposed in parallel and having different respective wavelength amplification regions respectively amplify light signals emitted from the optical divider, and an optical combiner based on long wavelength (or short wavelength) transmission type dielectric multi-layer filter combines light signals output from the respective amplifying sections. In another configuration of the optical amplifier, input signal light is divided using an optical divider based on a dielectric multi-layer filter of a long wavelength (or short wavelength) transmission type, and output signals from the divider are filtered using an optical filter connected in series to a short wavelength (or long wavelength) amplifier generating a loss in the long wavelength (or short wavelength) region of the light signals.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: June 24, 2003
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Hiroji Masuda, Junichi Kani, Noboru Takachio