Patents by Inventor Ryuuichi Ikematsu

Ryuuichi Ikematsu 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).

  • Optical transmission switching device
    Patent number: 7609728
    Abstract: Disclosed are the multiplex communication system and the method therefore. A fault detection part of a duplex switching device detects it as generation of fault when recognizable signals are not detected from a connected line within a prescribed time. When the fault detection part detects the generation of fault in the present system line, the line switching part switches the lines from the present line to the standby line to perform communication between a terminal device and another terminal device therethrough. Also, the fault detection part notifies the generation of fault to the other duplex switching device after a prescribed switching protection time has passed from the time of the fault detected by the fault detection part, so the selection of the lines becomes consistent.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: October 27, 2009
    Assignee: NEC Corporation
    Inventors: Toshiaki Arikawa, Ryuuichi Ikematsu, Shigekazu Harada, Hajima Ishikawa, Takahide Sugita, Hidetoshi Shinoda
  • Multiplex communication system and method
    Patent number: 7372804
    Abstract: Disclosed are the multiplex communication system and the method therefore. A fault detection part of a duplex switching device detects it as generation of fault when recognizable signals are not detected from a connected line within a prescribed time. When the fault detection part detects the generation of fault in the present system line, the line switching part switches the lines from the present line to the standby line to perform communication between a terminal device and another terminal device therethrough. Also, the fault detection part notifies the generation of fault to the other duplex switching device after a prescribed switching protection time has passed from the time of the fault detected by the fault detection part, so the selection of the lines becomes consistent.
    Type: Grant
    Filed: January 3, 2003
    Date of Patent: May 13, 2008
    Assignee: NEC Corporation
    Inventors: Toshiaki Arikawa, Ryuuichi Ikematsu, Shigekazu Harada, Hajime Ishikawa, Takahide Sugita, Hidetoshi Shinoda
  • Optical transmission switching device
    Publication number: 20060072923
    Abstract: Disclosed are the multiplex communication system and the method therefore. A fault detection part of a duplex switching device detects it as generation of fault when recognizable signals are not detected from a connected line within a prescribed time. When the fault detection part detects the generation of fault in the present system line, the line switching part switches the lines from the present line to the standby line to perform communication between a terminal device and another terminal device therethrough. Also, the fault detection part notifies the generation of fault to the other duplex switching device after a prescribed switching protection time has passed from the time of the fault detected by the fault detection part, so the selection of the lines becomes consistent.
    Type: Application
    Filed: November 21, 2005
    Publication date: April 6, 2006
    Inventors: Toshiaki Arikawa, Ryuuichi Ikematsu, Shigekazu Harada, Hajime Ishikawa, Takahide Sugita, Hidetoshi Shinoda
  • Multiplex communication system and method
    Publication number: 20030133712
    Abstract: Disclosed are the multiplex communication system and the method therefore. A fault detection part of a duplex switching device detects it as generation of fault when recognizable signals are not detected from a connected line within a prescribed time. When the fault detection part detects the generation of fault in the present system line, the line switching part switches the lines from the present line to the standby line to perform communication between a terminal device and another terminal device therethrough. Also, the fault detection part notifies the generation of fault to the other duplex switching device after a prescribed switching protection time has passed from the time of the fault detected by the fault detection part, so the selection of the lines becomes consistent.
    Type: Application
    Filed: January 3, 2003
    Publication date: July 17, 2003
    Applicant: NEC CORPORATION
    Inventors: Toshiaki Arikawa, Ryuuichi Ikematsu, Shigekazu Harada, Hajime Ishikawa, Takahide Sugita, Hidetoshi Shinoda