Patents Assigned to KDDI R & D Laboratories Inc.
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Patent number: 7366135Abstract: The present invention provides a radio channel assignment method where each node in a network assigns radio channels to respective radio links in a decentralized manner without inconsistency. The radio channel assignment method includes a step of assigning one of a pair of nodes terminating each radio link and the other thereof to an upper side and a lower side (Step S1), and a step that each radio node located to the upper side from at least one of radio links terminating at an own node assigns a frequency slot different from that of an adjacent link to a radio link locating an own node to the upper side (Step S5).Type: GrantFiled: March 5, 2003Date of Patent: April 29, 2008Assignee: KDDI R & D Laboratories Inc.Inventors: Satoshi Konishi, Shinobu Nanba, Yoji Kishi, Shinichi Nomoto
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Publication number: 20070211645Abstract: A method for classifying congestion paths based on packet delay in a plurality of paths between measurement nodes, has the following steps. First, it receives a measurement data unit including an origin node, a destination node, and a sent time and a received time in a received packet from the measurement node. Then, it arranges the measurement data units of the same origin node in order of sent time, and extracts a pair of measurement data units of which an interval time between the sent times of adjacent measurement data units is less than the threshold time. Then, it arranges the measurement data units of the same destination node in order of the received time, and extracts a pair of measurement data units of which an interval time between the received times of adjacent measurement data units is less than the threshold time.Type: ApplicationFiled: March 1, 2007Publication date: September 13, 2007Applicant: KDDI R&D LABORATORIES, INC.Inventors: Atsuo Tachibana, Shigehiro Ano, Toru Hasegawa
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Patent number: 7196833Abstract: An apparatus for simultaneous OTDM demultiplexing, electrical clock recovery and optical clock generation, and optical clock recovery using a traveling-wave electroabsorption modulator. The apparatus includes a TW-EAM and a PLL coupled thereto. The TW-EAM includes a first, a second, a third, and a fourth. The first port is used for an optical input and the third port is used for optical output. The second port is coupled to an input, and the fourth port is coupled to an output, of the PLL. When the first port receives optical input, the second port produces a photocurrent to be applied to the PLL, and the fourth port receives a recovered clock produced by the PLL, and the third port produces demultiplexed data and an optical clock. Using the same configuration, the apparatus produces a recovered optical clock signal.Type: GrantFiled: August 23, 2005Date of Patent: March 27, 2007Assignees: KDDI R&D Laboratories, Inc., The Regents of the University of CaliforniaInventors: Zhaoyang Hu, Kohsuke Nishimura, Hsu-Feng Chou, Daniel J. Blumenthal, John E. Bowers, Ryo Inohara, Masashi Usami
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Patent number: 7184189Abstract: An apparatus for simultaneous OTDM demultiplexing, electrical clock recovery and optical clock generation, and optical clock recovery using a traveling-wave electroabsorption modulator. The apparatus includes a TW-EAM and a PLL coupled thereto. The TW-EAM includes a first, a second, a third, and a fourth. The first port is used for an optical input and the third port is used for optical output. The second port is coupled to an input, and the fourth port is coupled to an output, of the PLL. When the first port receives optical input, the second port produces a photocurrent to be applied to the PLL, and the fourth port receives a recovered clock produced by the PLL, and the third port produces demultiplexed data and an optical clock. Using the same configuration, the apparatus produces a recovered optical clock signal.Type: GrantFiled: August 23, 2005Date of Patent: February 27, 2007Assignees: KDDI R&D Laboratories, Inc., The Regents of the University of CaliforniaInventors: Zhaoyang Hu, Kohsuke Nishimura, Hsu-Feng Chou, Daniel J. Blumenthal, John E. Bowers, Ryo Inohara, Masashi Usami
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Patent number: 7123941Abstract: A radio LAN master station system which provides long distance communication and suffers from small interference by another system located inside and/or outside of a service area comprises a transceiver, and a plurality of directional antennas each directed to a respective section with some angular spacing, through a power distributor which couples said transceiver with said antennas. Polarization plane of any antenna is orthogonal to polarization plane of an adjacent antenna.Type: GrantFiled: February 27, 2002Date of Patent: October 17, 2006Assignee: KDDI R&D Laboratories Inc.Inventors: Tadayuki Fukuhara, Hiroyasu Ishikawa, Takayuki Warabino, Naoki Fuke, Keizo Sugiyama, Hideyuki Shinonaga
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Publication number: 20060056854Abstract: An apparatus for simultaneous OTDM demultiplexing, electrical clock recovery and optical clock generation, and optical clock recovery using a traveling-wave electroabsorption modulator. The apparatus includes a TW-EAM and a PLL coupled thereto. The TW-EAM includes a first, a second, a third, and a fourth. The first port is used for an optical input and the third port is used for optical output. The second port is coupled to an input, and the fourth port is coupled to an output, of the PLL. When the first port receives optical input, the second port produces a photocurrent to be applied to the PLL, and the fourth port receives a recovered clock produced by the PLL, and the third port produces demultiplexed data and an optical clock. Using the same configuration, the apparatus produces a recovered optical clock signal.Type: ApplicationFiled: August 23, 2005Publication date: March 16, 2006Applicants: KDDI R&D Laboratories Inc., The Regents of the University of CaliforniaInventors: Zhaoyang Hu, Kohsuke Nishimura, Hsu-Feng Chou, Daniel Blumenthal, John Bowers, Ryo Inohara, Masashi Usami
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Publication number: 20060056853Abstract: An apparatus for simultaneous OTDM demultiplexing, electrical clock recovery and optical clock generation, and optical clock recovery using a traveling-wave electroabsorption modulator. The apparatus includes a TW-EAM and a PLL coupled thereto. The TW-EAM includes a first, a second, a third, and a fourth. The first port is used for an optical input and the third port is used for optical output. The second port is coupled to an input, and the fourth port is coupled to an output, of the PLL. When the first port receives optical input, the second port produces a photocurrent to be applied to the PLL, and the fourth port receives a recovered clock produced by the PLL, and the third port produces demultiplexed data and an optical clock. Using the same configuration, the apparatus produces a recovered optical clock signal.Type: ApplicationFiled: August 23, 2005Publication date: March 16, 2006Applicants: KDDI R&D Laboratories Inc., The Regents of the University of CaliforniaInventors: Zhaoyang Hu, Kohsuke Nishimura, Hsu-Feng Chou, Daniel Blumenthal, John Bowers, Ryo Inohara, Masashi Usami
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Patent number: 6992981Abstract: A communication system capable of avoiding congestion in transmission of moving image data, includes (1) at least one receiving terminal, (2) a moving image delivery device for delivering moving image data to the at least one receiving terminal, (3) a moving image conversion device which has at least one moving image conversion unit for converting, in accordance with conversion parameters, the moving image data sent from the moving image delivery device, a conversion parameter setting unit for determining the conversion parameters, and a monitored result receiving unit, and (4) at least one packet switching node which has at least one data storage unit for preliminarily storing the moving image data from the moving image conversion device to be sent to the at least one receiving terminal, a data amount monitor unit for monitoring an amount of the moving image data stored in the at least one data storage unit to judge that the monitored data amount reaches a first threshold, and a monitored result sending unitType: GrantFiled: January 7, 2002Date of Patent: January 31, 2006Assignee: KDDI R & D Laboratories Inc.Inventors: Daisuke Morikawa, Shinji Ota, Shouichi Yamazaki, Masayoshi Ohashi, Takayuki Warabino, Hajime Nakamura, Hideaki Iwashita
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Publication number: 20050195331Abstract: The present invention intends to provide a classification apparatus for broadcasted sport videos for classifying various scenes constituting a sport video, depending on the importance level without being limited to any particular sport video by using visual and audio features. A sport video classification processing portion determines and classifies a play scene, a close-up shot and the like using an audio and a color feature extracted from motion picture data. Because the determination of the most frequent color can be changed adaptively for each inputted sport video, it is not necessary to determine any particular color to the most frequent color previously.Type: ApplicationFiled: March 2, 2005Publication date: September 8, 2005Applicant: KDDI R&D Laboratories, Inc.Inventors: Masaru Sugano, Hiromasa Yanagihara, Yasuyuki Nakajima
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Publication number: 20050018271Abstract: An apparatus for simultaneous OTDM demultiplexing, electrical clock recovery and optical clock generation, and optical clock recovery using a traveling-wave electroabsorption modulator. The apparatus includes a TW-EAM and a PLL coupled thereto. The TW-EAM includes a first, a second, a third, and a fourth. The first port is used for an optical input and the third port is used for optical output. The second port is coupled to an input, and the fourth port is coupled to an output, of the PLL. When the first port receives optical input, the second port produces a photocurrent to be applied to the PLL, and the fourth port receives a recovered clock produced by the PLL, and the third port produces demultiplexed data and an optical clock. Using the same configuration, the apparatus produces a recovered optical clock signal.Type: ApplicationFiled: March 16, 2004Publication date: January 27, 2005Applicants: KDDI R&D Laboratories Inc., The Regents of the University of CaliforniaInventors: Zhaoyang Hu, Kohsuke Nishimura, Hsu-Feng Chou, Daniel Blumenthal, John Bowers, Ryo Inohara, Masashi Usami
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Publication number: 20040223052Abstract: The present invention provides a scene classification apparatus for classifying uncompressed or compressed video into various types of scenes at low cost and with high accuracy using characteristics of a video and audio characteristics accompanied by the video. When video are compressed data, their motion intensity, spatial distribution of motion and histogram of motion direction are detected by using values of motion vectors of predictive coding images existing in respective shots, and the respective shots of the video are classified into a dynamic scene, a static scene, a slow scene, a highlight scene, a zooming scene, a panning scene, a commercial scene and the like based on the motion intensity, the spatial distribution of motion, the histogram of motion direction and shot density.Type: ApplicationFiled: September 26, 2003Publication date: November 11, 2004Applicant: KDDI R&D Laboratories, INC.Inventors: Masaru Sugano, Yasuyuki Nakajima, Hiromasa Yanagihara
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Patent number: 6813379Abstract: A shape entropy, a motion vector entropy, and a texture entropy of a certain area i of an input image are derived by a shape entropy calculation section, a motion vector entropy calculation section, and a texture entropy calculation section, respectively. Among them, the texture entropy is derived by taking an allowed value n of encoding degradation given according to a limit (encoding rate) of an entropy which can transmitted into consideration. Therefore, a generated entropy obtained by adding up the shape entropy, the motion vector entropy, and the texture entropy becomes a value according to the encoding rate. In such optimizing segmentation encoding as to minimize the generated entropy, therefore, it becomes possible to conduct segmentation according to the encoding rate.Type: GrantFiled: August 21, 2001Date of Patent: November 2, 2004Assignee: KDDI R&D Laboratories, Inc.Inventors: Ryoichi Kawada, Atsushi Koike, Shuichi Matsumoto
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Publication number: 20040190511Abstract: It is made possible to concretely estimate actual transmission bit rate in a frame of grasping a line state by using a report packet.Type: ApplicationFiled: March 18, 2004Publication date: September 30, 2004Applicant: KDDI R&D Laboratories, Inc.Inventors: Satoshi Miyaji, Yasuhiro Takishima, Yasuyuki Nakajima
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Publication number: 20030176193Abstract: The present invention provides a radio channel assignment method where each node in a network assigns radio channels to respective radio links in a decentralized manner without inconsistency.Type: ApplicationFiled: March 5, 2003Publication date: September 18, 2003Applicant: KDDI R&D LABORATORIES, INC.Inventors: Satoshi Konishi, Shinobu Nanba, Yoji Kishi, Shinichi Nomoto
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Publication number: 20020128046Abstract: A radio LAN master station system which provides long distance communication and suffers from small interference by another system located inside and/or outside of a service area comprises a transceiver, and a plurality of directivity antennas each directed to respective section with some angular spacing, through a power distributor which couples said transceiver with said antennas. Polarization plane of any antenna is orthogonal to polarization plane of an adjacent antenna.Type: ApplicationFiled: February 27, 2002Publication date: September 12, 2002Applicant: KDDI R&D Laboratories Inc.Inventors: Tadayuki Fukuhara, Hiroyasu Ishikawa, Takayuki Warabino, Naoki Fuke, Keizo Sugiyama, Hideyuki Shinonaga
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Publication number: 20020089928Abstract: A communication system capable of avoiding congestion in transmission of moving image data, includes (1) at least one receiving terminal, (2) a moving image delivery device for delivering moving image data to the at least one receiving terminal, (3) a moving image conversion device which has at least one moving image conversion unit for converting, in accordance with conversion parameters, the moving image data sent from the moving image delivery device, a conversion parameter setting unit for determining the conversion parameters, and a monitored result receiving unit, and (4) at least one packet switching node which has at least one data storage unit for preliminarily storing the moving image data from the moving image conversion device to be sent to the at least one receiving terminal, a data amount monitor unit for monitoring an amount of the moving image data stored in the at least one data storage unit to judge that the monitored data amount reaches a first threshold, and a monitored result sending unitType: ApplicationFiled: January 7, 2002Publication date: July 11, 2002Applicant: KDDI R&D Laboratories Inc.Inventors: Daisuke Morikawa, Shinji Ota, Shouichi Yamazaki, Masayoshi Ohashi, Takayuki Warabino, Hajime Nakamura, Hideaki Iwashita
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Publication number: 20020041711Abstract: A shape entropy, a motion vector entropy, and a texture entropy of a certain area i of an input image are derived by a shape entropy calculation section, a motion vector entropy calculation section, and a texture entropy calculation section, respectively. Among them, the texture entropy is derived by taking an allowed value n of encoding degradation given according to a limit (encoding rate) of an entropy which can transmitted into consideration. Therefore, a generated entropy obtained by adding up the shape entropy, the motion vector entropy, and the texture entropy becomes a value according to the encoding rate. In such optimizing segmentation encoding as to minimize the generated entropy, therefore, it becomes possible to conduct segmentation according to the encoding rate.Type: ApplicationFiled: August 21, 2001Publication date: April 11, 2002Applicant: KDDI R&D LABORATORIES, INC.Inventors: Ryoichi Kawada, Atsushi Koike, Shuichi Matsumoto