Patents by Inventor Koji Tanonaka

Koji Tanonaka 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: 20170047990
    Abstract: In a wavelength division multiplexing transmission system, a controller of a relay node of a post-stage notifies level decrease information to a transmission node, upon detecting a decrease in a level of a wavelength in a wavelength multiplex signal received from the transmission node of a pre-stage by the optical channel monitor of the transmission node. The controller of the transmission node of the pre-stage determines that a failure occurs in the wavelength of the transponder of the transmission node, upon detecting a decrease in the level of the wavelength in the wavelength multiplex signal transmitted to the relay node by the optical channel monitor of the transmission node and upon receiving the level decrease information for the wavelength from the relay node. Therefore, a wavelength channel failure in the transponder can be determined in a preferable manner.
    Type: Application
    Filed: August 15, 2016
    Publication date: February 16, 2017
    Applicant: FUJITSU LIMITED
    Inventors: Akihisa KAWAGUCHI, Koji TANONAKA, Tonoyuki SUZUKI, Reiko SATO, Akihide KASEZAWA, Shoichi MURAKAMI, Ryo KARUBE
  • Patent number: 8693874
    Abstract: A transmission system is provided with a transmission apparatus that outputs an ASE light from a transmission light amplifier and with a reception apparatus provided with: a tilt detection unit that detects the optical strength levels of at least two probe lights having different wavelengths from a received ASE light; and a reception light amplifier that performs a first-order tilt correction on light to be output in a linear manner so as to reduce the difference in the optical strength level of the two probe lights detected by the tilt detection unit.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: April 8, 2014
    Assignees: Fujitsu Limited, Fujitsu Telecom Networks Limited
    Inventors: Tomoyuki Suzuki, Kenji Watanabe, Koji Tanonaka, Akihisa Kawaguchi, Takehiro Fujita
  • Patent number: 8326147
    Abstract: An integrated transmission apparatus includes a plurality of optical supervisory channel (OSC) processing units for processing OSC signals contained in a wavelength division multiplexing (WDM) signal received from a WDM network and a switching unit for performing the path control of synchronous digital hierarchy (SDH) frames. An OSC processing unit transmits the SDH frame, containing wavelength information indicated by, to the switching unit. Another OSC processing unit acquires the SDH frame, containing wavelength information, from the switching unit and sets an OSC signal which is to be appended to the WDM signal to be transmitted, based on the wavelength information.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: December 4, 2012
    Assignee: Fujitsu Telecom Networks Limited
    Inventors: Koji Tanonaka, Kenji Watanabe, Tomoyuki Suzuki, Akihisa Kawaguchi
  • Publication number: 20110008049
    Abstract: An integrated transmission apparatus includes a plurality of optical supervisory channel (OSC) processing units for processing OSC signals contained in a wavelength division multiplexing (WDM) signal received from a WDM network and a switching unit for performing the path control of synchronous digital hierarchy (SDH) frames. An OSC processing unit transmits the SDH frame, containing wavelength information indicated by, to the switching unit. Another OSC processing unit acquires the SDH frame, containing wavelength information, from the switching unit and sets an OSC signal which is to be appended to the WDM signal to be transmitted, based on the wavelength information.
    Type: Application
    Filed: March 15, 2010
    Publication date: January 13, 2011
    Applicant: FUJITSU TELECOM NETWORKS LIMITED
    Inventors: Koji Tanonaka, Kenji Watanabe, Tomoyuki Suzuki, Akihisa Kawaguchi
  • Publication number: 20100322633
    Abstract: A transmission system is provided with a transmission apparatus that outputs an ASE light from a transmission light amplifier and with a reception apparatus provided with: a tilt detection unit that detects the optical strength levels of at least two probe lights having different wavelengths from a received ASE light; and a reception light amplifier that performs a first-order tilt correction on light to be output in a linear manner so as to reduce the difference in the optical strength level of the two probe lights detected by the tilt detection unit.
    Type: Application
    Filed: April 23, 2010
    Publication date: December 23, 2010
    Applicants: FUJITSU TELECOM NETWORKS LIMITED, FUJITSU LIMITED
    Inventors: Tomoyuki Suzuki, Kenji Watanabe, Koji Tanonaka, Akihisa Kawaguchi, Takehiro Fujita
  • Patent number: 6928088
    Abstract: A transmission apparatus utilizing an SDH is provided. The transmission apparatus includes a processing unit controlling the transmission apparatus, an SSM extraction unit extracting a first SSM from an input signal, and a selector selecting either of the first SSM and a second SSM set by the processing unit. The transmission apparatus can add an incoming SSM function, for instance, to an external 2 Mbps SSM function in addition to an assumed SSM function. Accordingly, the transmission apparatus can conform to the ITU-T G.781 Recommendation by utilizing a related-art synchronization function.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: August 9, 2005
    Assignee: Fujitsu Limited
    Inventors: Koji Tanonaka, Naoto Kidoku, Motoshi Hamasaki
  • Publication number: 20040148437
    Abstract: A method of establishing synchronization in a network including a node apparatus conforming to a first scheme and a node apparatus conforming to a second scheme is disclosed. The first scheme and the second scheme implement different synchronous state indication codes for establishing the synchronous network. By converting a synchronous state indication code from a node apparatus conforming to one scheme into a synchronous state indication code suitable for a neighboring node apparatus conforming to the other scheme, a node apparatus conforming to one of the schemes can be cascaded into a network conforming to the other scheme, and network synchronization can be established.
    Type: Application
    Filed: November 20, 2003
    Publication date: July 29, 2004
    Inventor: Koji Tanonaka
  • Publication number: 20020027903
    Abstract: A transmission apparatus utilizing an SDH is provided. The transmission apparatus includes a processing unit controlling the transmission apparatus, an SSM extraction unit extracting a first SSM from an input signal, and a selector selecting either of the first SSM and a second SSM set by the processing unit. The transmission apparatus can add an incoming SSM function, for instance, to an external 2 Mbps SSM function in addition to an assumed SSM function. Accordingly, the transmission apparatus can conform to the ITU-T G.781 Recommendation by utilizing a related-art synchronization function.
    Type: Application
    Filed: March 20, 2001
    Publication date: March 7, 2002
    Inventors: Koji Tanonaka, Naoto Kidoku, Motoshi Hamasaki
  • Patent number: 6173023
    Abstract: The invention concerns synchronization equipment; more particularly, the invention is directed to the provision of synchronization equipment which, after simple hardware installation and software setting, establishes a synchronization network with an existing network, SDH elements, etc. that do not support SSMB.
    Type: Grant
    Filed: March 11, 1998
    Date of Patent: January 9, 2001
    Assignee: Fujitsu Limited
    Inventors: Koji Tanonaka, Naoto Kidoku, Toshikazu Magome, Hiroyuki Suzuki