Patents by Inventor Tooru Shima

Tooru Shima 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).

  • Method of activating optical communication system, channel increasing/decreasing method, and computer-readable recording medium
    Patent number: 6839160
    Abstract: The invention relates to a method of activating an optical communication system comprising a plurality of optical amplifiers having an optical amplifier, between optical transmission lines in which wavelength-division multiplex optical signals are transmitted. The method comprises steps of: generating a desired slope in a desired wavelength range of a gain wavelength curve of the optical amplifier; adjusting an output of the optical amplifier to a desired output level; performing the above two steps in a plurality of optical repeater stations, the steps being carried out in sequence from the first to the last optical repeater stations; and adjusting a level in each optical signal in the wavelength-division multiplex optical signal so as to have substantially constant optical signal-to-noise ratios in the optical signals to be received. Activating the optical communication system according to this procedure allows proper execution of gain slope compensation, output control, and pre-emphasis control.
    Type: Grant
    Filed: April 26, 2002
    Date of Patent: January 4, 2005
    Assignee: Fujitsu Limited
    Inventors: Takashi Tsuda, Kazuo Yamane, Makoto Murakami, Tooru Shima, Tooru Matsumoto, Hiroyuki Iwaki, Kazuto Imai
  • Method of activating optical communication system, channel increasing/decreasing method, and computer-readable recording medium
    Publication number: 20020154359
    Abstract: The invention relates to a method of activating an optical communication system comprising a plurality of optical amplifiers having an optical amplifier, between optical transmission lines in which wavelength-division multiplex optical signals are transmitted. The method comprises steps of: generating a desired slope in a desired wavelength range of a gain wavelength curve of the optical amplifier; adjusting an output of the optical amplifier to a desired output level; performing the above two steps in a plurality of optical repeater stations, the steps being carried out in sequence from the first to the last optical repeater stations; and adjusting a level in each optical signal in the wavelength-division multiplex optical signal so as to have substantially constant optical signal-to-noise ratios in the optical signals to be received. Activating the optical communication system according to this procedure allows proper execution of gain slope compensation, output control, and pre-emphasis control.
    Type: Application
    Filed: April 26, 2002
    Publication date: October 24, 2002
    Applicant: FUJITSU LIMITED
    Inventors: Takashi Tsuda, Kazuo Yamane, Makoto Murakami, Tooru Shima, Tooru Matsumoto, Hiroyuki Iwaki, Kazuto Imai