Patents by Inventor Kenji Kawakita

Kenji Kawakita 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: 20220173813
    Abstract: An object is to provide an optical communication system and an optical communication method that are capable of, when assigning wavelengths on a per-service basis and providing services on a per-area basis, preventing degradation of signal quality due to linear crosstalk and preventing an increase in cost and size. An optical communication system according to the present invention includes an optical splitter 300 connecting N first ports and M second ports by a combination of 2×2 fiber optical splitters, N and M each being an integer of two or more, where wavelengths of optical signals to be received are limited for each group of optical receivers 106, by using a correlation between a fused extension length of at least one 2×2 fiber optical splitter directly connected to the first port, among the 2×2 fiber optical splitters, and wavelength output characteristics of the second port of the optical splitter 300.
    Type: Application
    Filed: March 6, 2020
    Publication date: June 2, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Atsuko KAWAKITA, Kazutaka HARA, Yasutaka KIMURA, Kenji HORIKAWA, Hiroyuki FURUKAWA
  • Publication number: 20220166532
    Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.
    Type: Application
    Filed: March 6, 2020
    Publication date: May 26, 2022
    Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Atsuko KAWAKITA, Kazutaka HARA, Yasutaka KIMURA, Kenji HORIKAWA, Hiroyuki FURUKAWA
  • Patent number: 6816495
    Abstract: A communication network including connection switching exchanges, such as an ATM, a connection management apparatus is provided in a network management unit of a communication network. A group of logical connections with a fixed group size and consecutive identifiers assigned to the connections is treated as a unit. The number of logical connections in the group is an integer with a power of 2. The logical connections and connection identifiers assigned to the logical connections are set up and released in connection setting units each equal to a multiple of the group size in a unitary manner across the network. A priority level is assigned to each connection setting unit. When logical connections have been set for connection setting units sharing the same connection identifiers, logical connections with the shared connection identifiers pertaining to a connection setting unit with a smaller size is considered to be valid.
    Type: Grant
    Filed: February 6, 2002
    Date of Patent: November 9, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Nishikado, Kenji Kawakita, Takanori Miyamoto
  • Publication number: 20020071437
    Abstract: A communication network including connection switching exchanges, such as an ATM, a connection management apparatus is provided in a network management unit of a communication network. A group of logical connections with a fixed group size and consecutive identifiers assigned to the connections is treated as a unit. The number of logical connections in the group is an integer with a power of 2. The logical connections and connection identifiers assigned to the logical connections are set up and released in connection setting units each equal to a multiple of the group size in a unitary manner across the network. A priority level is assigned to each connection setting unit. When logical connections have been set for connection setting units sharing the same connection identifiers, logical connections with the shared connection identifiers pertaining to a connection setting unit with a smaller size is considered to be valid.
    Type: Application
    Filed: February 6, 2002
    Publication date: June 13, 2002
    Inventors: Takashi Nishikado, Kenji Kawakita, Takanori Miyamoto
  • Patent number: 6396808
    Abstract: A signal processing method for an ATM switching network formed by connecting a plurality of ATM switching networks in which header conversion tables of line interfaces can be rewritten by control cells, includes in response to occurrence of an abnormality in a call control processor of a ATM switching system A, informing an ATM switching system B of the occurrence of the abnormality, transferring call control information in the ATM switching system A to the ATM switching system B, rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system A and thereby transferring signal channel cells arriving at the ATM switching system A after occurrence of the abnormality to the ATM switching system B, and rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system B and thereby making a call control proces
    Type: Grant
    Filed: March 6, 2000
    Date of Patent: May 28, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Masao Kunimoto, Kenji Kawakita, Shinichi Iwaki, Satoshi Shimizu
  • Patent number: 6366582
    Abstract: In a communication network including connection switching exchanges such as an ATM, a connection management means is provided in a network management unit of the communication network. A group of logical connections with a fixed group size and consecutive identifiers assigned to the connections is treated as a unit. The number of logical connections in such a group is an integer with power of 2. Logical connections in the communication network and connection identifiers assigned to the logical connections are set up and released in connection setting units each equal to a multiple of the group size in a unitary manner across the whole communication network. A priority level is assigned to each connection setting unit. When logical connections have been set for a plurality of connection setting units sharing the same connection identifiers, logical connections with the shared connection identifiers pertaining to a connection setting unit with a smallest size is considered to be valid.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: April 2, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Nishikado, Kenji Kawakita, Takanori Miyamoto
  • Publication number: 20020027924
    Abstract: This invention provides a router device facilitating a management of connection of a managing person and assuring a communication quality of each of the connections. The router device 1 determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.
    Type: Application
    Filed: August 9, 2001
    Publication date: March 7, 2002
    Inventors: Hidehiro Fukushima, Kenji Kawakita, Naoya Ikeda, Masashi Kamegaya
  • Patent number: 6292489
    Abstract: A router device facilitates management of connection of a manager and assures communication quality of each of the connections. The router device determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.
    Type: Grant
    Filed: January 6, 2000
    Date of Patent: September 18, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hidehiro Fukushima, Kenji Kawakita, Naoya Ikeda, Masashi Kamegaya
  • Patent number: 6094433
    Abstract: A signal processing method for an ATM switching network formed by connecting a plurality of ATM switching networks in which header conversion tables of line interfaces can be rewritten by control cells, includes in response to occurrence of an abnormality in a call control processor of a ATM switching system A, informing an ATM switching system B of the occurrence of the abnormality, transferring call control information in the ATM switching system A to the ATM switching system B, rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system A and thereby transferring signal channel cells arriving at the ATM switching system A after occurrence of the abnormality to the ATM switching system B, and rewriting header conversion tables included in a plurality of line interfaces of the ATM switching system A by using control cells generated by the ATM switching system B and thereby making a call control proces
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: July 25, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Masao Kunimoto, Kenji Kawakita, Shinichi Iwaki, Satoshi Shimizu
  • Patent number: 6034964
    Abstract: A router device facilitates management of connection of a manager and assures communication quality of each of the connections. The router device determines a communication quality required by the communication of the packet in reference to a protocol information, an application acknowledging information and a priority information, transmits the control packet having the determined communication quality set therein to another router device contained in the same connection and further performs a traffic control (a preferential processing of a packet or the like) satisfying a communication quality indicated by the transmitted or received control packet in respect to the packet of the aforesaid connection.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: March 7, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hidehiro Fukushima, Kenji Kawakita, Naoya Ikeda, Masashi Kamegaya
  • Patent number: 6021134
    Abstract: A cell/packet assembly and disassembly apparatus is provided for efficiently connecting a line in a line switching system to an ATM network or a packet network, without causing congestion, to transmit and receive cells or packets therebetween. The cell/packet assembly and disassembly apparatus, upon detecting a call setting request outputted from a line switch board in response to a call originated from a terminal, starts cell assembly and cell disassembly of user information transmitted and received between a channel on a line in the line switching system corresponding to the call setting request and a virtual channel on the ATM network assigned to the channel.
    Type: Grant
    Filed: October 14, 1997
    Date of Patent: February 1, 2000
    Assignees: Hitachi, Ltd., Hitachi Communications Systems, Inc.
    Inventors: Masashi Hiraiwa, Satoru Inazawa, Tatsuo Mochinaga, Kenji Kawakita
  • Patent number: 5764911
    Abstract: A system is provided for building, operating, and managing a virtual network which integrates the configuration, the operation, and the management of plural information devices connected to a network. The system includes agents for operating, and managing information devices in the respective devices, a physical manager for building, operating, and managing the information devices, and a logical manager for logically building, operating, and managing the information devices. The agent operates to control the settings and the change of the information device in which the agent is mounted and communicates the information with the physical manager. The physical manager operates to manage the agent of each information device and communicates the information with a user and the logical manager.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: June 9, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Tezuka, Shigeru Miyake, Kenji Kawaguchi, Satoshi Miyazaki, Kenji Kawakita, Takashi Kagei, Akira Mineo, Keizo Mizuguchi
  • Patent number: 5734653
    Abstract: A cell/packet assembly and disassembly apparatus is provided for efficiently connecting a line in a line switching system to an ATM network or a packet network, without causing congestion, to transmit and receive cells or packets therebetween. The cell/packet assembly and disassembly apparatus, upon detecting a call setting request outputted from a line switch board in response to a call originated from a terminal, starts cell assembly and cell disassembly of user information transmitted and received between a channel on a line in the line switching system corresponding to the call setting request and a virtual channel on the ATM network assigned to the channel.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: March 31, 1998
    Assignees: Hitachi, Ltd., Hitachi Communication Systems, Inc.
    Inventors: Masashi Hiraiwa, Satoru Inazawa, Tatsuo Mochinaga, Kenji Kawakita
  • Patent number: 5729530
    Abstract: An ATM switch capable of preventing the network resource from being wasted during the occurrence of an overcrowding condition. In the ATM switch, both a message type and a processing mode are stored in correspondence to the connections. When the discarding of a cell occurs, the connection to which the discarded cell belongs is set to a discard mode by a cell discard controlling circuit, and each cell constituting the same message as that of the discarded cell out of the subsequent cells is discarded, and when a demarkation of the message has been detected, the processing mode is returned to a transfer mode, whereby the subsequent received cells are transferred in a normal manner. Thus, the cell which has become useless for a reception terminal is discarded in the network.
    Type: Grant
    Filed: December 6, 1995
    Date of Patent: March 17, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Kawaguchi, Kenji Kawakita, Hiroshi Izuha
  • Patent number: 5583216
    Abstract: Provided is a process for preparing a cephem compound of the formula: ##STR1## wherein R.sup.3 is hydrogen or methoxy, R.sup.4 is hydrogen or a residue of a nucleophilic compound, R.sup.5 is hydroxyl or a protected hydroxyl, and R.sup.8 is hydrogen or halogen, or a pharmaceutically acceptable salt or ester thereof, which comprises introducing an acyl group of the formula: ##STR2## wherein R.sup.5 and R.sup.8 are as defined above into the amino group of the molecule of the formula: ##STR3## wherein R.sup.3 and R.sup.4 are as defined above or a salt or ester thereof.
    Type: Grant
    Filed: January 8, 1990
    Date of Patent: December 10, 1996
    Assignee: Takeda Chemical Industries, Ltd.
    Inventors: Michihiko Ochiai, Taiiti Okada, Osami Aki, Akira Morimoto, Kenji Kawakita, Yoshihiro Matsushita
  • Patent number: 5517647
    Abstract: Information of a plurality of operation modes is stored in memory. Information of temporary protocols and true protocols is associated with event numbers and processing state numbers, then stored in a status transition table circuit. When an event number and a processing state number are set in an input register, a CPU selects a temporary protocol according to the event number and processing state number. Then, the CPU retrieves an operation mode associated with the temporary protocol from memory, selects a true protocol according to the retrieved operation mode, then executes information processing according to the true protocol.
    Type: Grant
    Filed: July 22, 1992
    Date of Patent: May 14, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Seiji Kamada, Kenji Kawakita
  • Patent number: 5388239
    Abstract: A system of adding an operand address included in an instruction word to the contents of a modification register to obtain an effective address, wherein address data which designates each of a plurality of data tables constituted with prescribed storage capacity, is stored in a plurality of modification registers. Prescribed address data of one of the plurality of modification registers is selected based on the instruction word. The effective address for addressing the operand is obtained by adding the prescribed address data of the one of the plurality of modification registers to address data included in the operand address. The address data included in the operand address designates addresses which correspond to addresses of the plurality of data tables.
    Type: Grant
    Filed: March 12, 1991
    Date of Patent: February 7, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Iimura, Sakae Miki, Shunji Shimada, Michio Hara, Kenjirou Yasunari, Hiroshi Takahashi, Kenichi Kimura, Akira Ikuta, Kenji Kawakita
  • Patent number: 5306601
    Abstract: Herein is provided a fine pattern forming method which is prevented from the charging-up phenomenon at the time of electric charged beam writing owing to the use of a polyalkylthiophene type conductive polymeric substance or a quaternary ammonium ion type polymeric substance in a monolayer or multilayer resist.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: April 26, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuhiko Hashimoto, Taichi Koizumi, Kenji Kawakita, Noboru Nomura
  • Patent number: 5278836
    Abstract: A multichannel communication processing system having line control apparatus means for analyzing receiving frames and channel-controlling transmitting frames, DMA control apparatus for transferring the data not via a host processor but directly to a main memory, a memory for storing a variety of data and a communication protocol processing program, a CPU for controlling the communication processing system as a whole and line correspondence apparatus including line correspondence units provided between the lines and the line control apparatus whereby serial interfaces with channels of the plurality of lines are effected.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: January 11, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Iimura, Sakae Miki, Kenji Kawakita
  • Patent number: 5214642
    Abstract: An adaptation processing apparatus for assembling received data units of a fixed length to provide variable length data units and transmitting the variable length data units to a plurality of variable length data unit processors while assembling variable length data units received from said plurality of the variable length data unit processors to provide fixed length data units for transmission thereof. An ATM switching system includes the adaptation processing apparatus, a signal processing unit including the plurality of variable length data unit processors mentioned above, and first-in first-out mechanisms for the variable length data units provided in the adaptation processing apparatus in association with every one of the plural variable length data unit processors.
    Type: Grant
    Filed: January 23, 1991
    Date of Patent: May 25, 1993
    Assignees: Hitachi, Ltd., Nippon Telegraph and Telephone Corporation
    Inventors: Masao Kunimoto, Jiro Kashio, Kenji Kawakita, Shinobu Gohara, Shinichi Iwaki, Hiroyuki Ichikawa