Patents by Inventor Naohiro Sakakida

Naohiro Sakakida 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).

  • Patent number: 8634426
    Abstract: When multiple SDH/SONET frame are accumulated and then lower-order path information removed from multiple frames is multiplexed into the same packet to achieve better transmission efficiency during packetization, the delay for accumulating increases. Disclosed is a transmission device that packetizes an SDH/SONET lower-order path with timing which is an integer factor of 1 cycle of the SDH frame. In this case, the destination loads the same multiple lower-order path in one packet. The result is that delay time accompanying lower-order path packetization is kept to less than the time of 1 cycle of the SDH frame, and the efficiency with which lower-order paths are accommodated in packets is further increased. The result is that improved transmission efficiency is realized.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: January 21, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Yoshio Nogi, Masatoshi Shibasaki, Naohiro Sakakida, Yoshihiro Ashi, Kazutaka Sakai
  • Publication number: 20120027023
    Abstract: When multiple SDH/SONET frame are accumulated and then lower-order path information removed from multiple frames is multiplexed into the same packet to achieve better transmission efficiency during packetization, the delay for accumulating increases. Disclosed is a transmission device that packetizes an SDH/SONET lower-order path with timing which is an integer factor of 1 cycle of the SDH frame. In this case, the destination loads the same multiple lower-order path in one packet. The result is that delay time accompanying lower-order path packetization is kept to less than the time of 1 cycle of the SDH frame, and the efficiency with which lower-order paths are accommodated in packets is further increased. The result is that improved transmission efficiency is realized.
    Type: Application
    Filed: November 14, 2008
    Publication date: February 2, 2012
    Inventors: Yoshio Nogi, Masatoshi Shibasaki, Naohiro Sakakida, Yoshihiro Ashi, Kazutaka Sakai
  • Patent number: 7769257
    Abstract: A signal speed converting apparatus to be connected to a WDM transmission end office, comprising a first interface connected to a first optical line group, a plurality of second interfaces connected to a second optical line group, and a speed converter. The first interface has a first framer for terminating a frame in a first format received from the first optical line group and outputting an information signal extracted from the received frames as a serial signal train or parallel signal trains. The speed converter converts the output signal from the first framer into transmission signal trains each including interleaved communication frame by cyclically distributing the output signal from the first framer to a plurality of internal lines. Each of the second interfaces has a second framer for converting the communication frame received from one of the internal lines into information frame in a second format to be transmitted to the second optical line group.
    Type: Grant
    Filed: August 22, 2008
    Date of Patent: August 3, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Nobuhiko Kikuchi, Takao Fukushima, Naohiro Sakakida, Hiroyuki Nakano
  • Publication number: 20090116839
    Abstract: A signal speed converting apparatus to be connected to a WDM transmission end office, comprising a first interface connected to a first optical line group, a plurality of second interfaces connected to a second optical line group, and a speed converter. The first interface has a first framer for terminating a frame in a first format received from the first optical line group and outputting an information signal extracted from the received frames as a serial signal train or parallel signal trains. The speed converter converts the output signal from the first framer into transmission signal trains each including interleaved communication frame by cyclically distributing the output signal from the first framer to a plurality of internal lines. Each of the second interfaces has a second framer for converting the communication frame received from one of the internal lines into information frame in a second format to be transmitted to the second optical line group.
    Type: Application
    Filed: August 22, 2008
    Publication date: May 7, 2009
    Inventors: Nobuhiko Kikuchi, Takao Fukushima, Naohiro Sakakida, Hiroyuki Nakano
  • Patent number: 7292785
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: November 7, 2006
    Date of Patent: November 6, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Publication number: 20070053687
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Application
    Filed: November 7, 2006
    Publication date: March 8, 2007
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 7167652
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: January 23, 2007
    Assignee: Hitachi, Ltd
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Publication number: 20040161189
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Application
    Filed: February 13, 2004
    Publication date: August 19, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 6728489
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: April 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Publication number: 20020024699
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Application
    Filed: July 19, 2001
    Publication date: February 28, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 6266169
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: October 1, 1999
    Date of Patent: July 24, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 6018405
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: January 25, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 6005699
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: September 11, 1997
    Date of Patent: December 21, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5875046
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: February 23, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5861972
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: January 19, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5812289
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-toelectric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: August 29, 1996
    Date of Patent: September 22, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5739932
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: April 14, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5671074
    Abstract: An optical transmission system accomplishes optical transmission over a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission over a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, and with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: September 23, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Kyoji Takeyari, Hiroyuki Nakano
  • Patent number: 5555477
    Abstract: An optical transmission system accomplishes optical transmission to a long distance by combining a multiplexing line terminal with optical amplifiers, linear repeaters, and regenerators with optical amplifiers combined together. The system also accomplishes the optical transmission to a short distance by directly connecting the linear terminals therebetween, with an electric-to-optic converter replaced by an electric-to-optic converter having a semiconductor amplifier, with an optic-to-electric converter by an optic-to-electric converter having an avalanche photodiode as light receiver, an with no use of any optical booster amplifier and optical preamplifier in the multiplexing line terminal. With these, the optical transmission system can be easily constructed depending on the transmission distance required.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: September 10, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Keiji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Ashi, Hironari Matsuda, Satoshi Aoki, Yukio Nakano, Masahiro Takatori, Toru Kazawa, Shinya Sasaki, Ryoji Takeyari, Hiroyuki Nakano
  • Patent number: 5500756
    Abstract: An optical repeater for realizing transmission of supervisory information of an optical fiber transmission system without the output power of an optical fiber amplifier being reduced, wherein a supervisory optical transmitter and optical receiver with a wavelength which is similar to the wavelength of the pumping light source of the optical fiber amplifier are mounted, and on the input side of the optical repeater, pumping light is multiplexed in the forward direction and a supervisory optical signal, which is multiplexed in wavelength and transmitted, is demultiplexed simultaneously by the first wavelength multi- and demultiplexer and they are received by the supervisory optical receiver, and on the output side of the optical repeater, pumping light is muitiplexed in the reverse direction and a supervisory optical signal outputted from the supervisory optical transmitter is multiplexed by the second wavelength multi- and demultiplexer.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: March 19, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Hideaki Tsushima, Shinya Sasaki, Yukio Nakano, Hiroyuki Nakano, Ryoji Tateyari, Hironari Matsuda, Kenji Tomooka, Naohiro Sakakida, Shin Nishimura, Yoshihiro Yano, Youichi Igarashi, Satoshi Aoki, Masahiro Takatori, Tohru Kazawa, Yoshihiro Ashi