Patents by Inventor Kazuo Sakagawa

Kazuo Sakagawa 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: 6421321
    Abstract: An apparatus and a method for transferring a packet flow having a plurality of packets in a communication network which includes plural subnetworks, first and second end systems connected to the respective subnetworks and a transit system for relaying the packet and a message between the first and second end systems through a default route, where the packet flow is forwarded from the first end system to the second end system or to a terminal connected to the second end system, in the first end system, determines it by collating the packet with a predetermined criterion whether to forward the packet flow through a shortcut path bypassing the default route and in dependence upon the determining, sends to the second end system through the default route, a request message requesting to set the shortcut path, along with an address of the first end system; in the second end system, requests the communication network to set the shortcut path between the first and second end systems in accordance with the request mes
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: July 16, 2002
    Assignee: Fujitsu Limited
    Inventors: Kazuo Sakagawa, Jun Ogawa
  • Patent number: 5774662
    Abstract: A originating terminal sends an ATM address interrogation request to a server if the ATM address of another party's terminal is unknown at the time of communication. Upon receiving the ATM address interrogation request from the terminal, the server refers to an ATM address table, searches the table for an ATM address corresponding to a protocol address contained in the interrogation request and notifies the originating terminal of this ATM address. If an ATM address corresponding to the protocol address has not been registered in the ATM address table, the server transfers (broadcasts) the ATM address interrogation request to all terminals. The server notifies the originating terminal of an ATM address obtained by an answer in response to this interrogation request and registers the ATM address in the ATM address table.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: June 30, 1998
    Assignee: Fujitsu Limited
    Inventor: Kazuo Sakagawa
  • Patent number: 5425019
    Abstract: The present invention is designed such that the communication quality of a currently connected normal call is deteriorated and the transmission of the normal call is delayed in a network when an emergent call is set. As a result, the required bandwidth of the emergent call is successfully reserved. Furthermore, the present invention is designed such that a deteriorated normal call is detoured to a detour circuit to improve the communication quality of the normal call. In the detouring process, one or more detour circuits are managed for each normal call so that the possibility of a successful detour to a detour circuit can be raised. Additionally, in the normal call detouring process, a plurality of detour circuits guarantee a normal call its communication quality even if a single detour circuit is not enough to meet the required bandwidth of a normal call.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: June 13, 1995
    Assignee: Fujitsu Limited
    Inventors: Akira Chugo, Masafumi Katoh, Ichiro Iida, Kazuo Sakagawa, Yoshihiro Watanabe, Toshio Soumiya
  • Patent number: 5287535
    Abstract: A switching node in a label multiplexing type switching network includes a switch for selectively coupling input logical communications paths and output logical communications paths with each other, m permanent logical communications paths being included in the input logical communications paths where m is an integer larger than or equal to 1, n permanent logical communications paths being included in the output logical communications paths where n is an integer larger than or equal to 1. The switch node includes a call control unit for receiving connection-oriented type information through any of the input logical communications paths and for controlling the switch so that the connection-oriented type information are selectively transferred to the output logical communications paths via the switch on the basis of routing address information related to the connection-oriented type information.
    Type: Grant
    Filed: May 7, 1992
    Date of Patent: February 15, 1994
    Assignee: Fujitsu Limited
    Inventors: Kazuo Sakagawa, Teruhisa Nakamura, Ichiro Iida
  • Patent number: 5068820
    Abstract: A data transfer system having a transfer discrimination circuit for discriminating the type of data transfer between an input/output channel device and I/O devices for a computer includes a transfer discrimination circuit. This circuit includes a edge detection unit operating in response to a tag signal supplied to the edge detection unit for detecting the trailing edge of the tag signal after a leading edge of the tag signal has passed. The edge detection unit having a leading edge detector, a trailing edge detector, a storage element, and logic gate circuits. A timing unit is included operating in response to the output of the edge detection unit for counting a predetermined time, along with a discrimination storage unit operating in response to the output of the timing unit for delivering an output indicating an interlock data transfer or an output indicating a data streaming feature data transfer.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: November 26, 1991
    Assignee: Fujitsu Limited
    Inventors: Satoshi Nojima, Kazuo Sakagawa, Hideo Suzuki
  • Patent number: RE39317
    Abstract: A originating terminal sends an ATM address interrogation request to a server if the ATM address of another party's terminal is unknown at the time of communication. Upon receiving the ATM address interrogation request from the terminal, the server refers to an ATM address table, searches the table for an ATM address corresponding to a protocol address contained in the interrogation request and notifies the originating terminal of this ATM address. If an ATM address corresponding to the protocol address has not been registered in the ATM address table, the server transfers (broadcasts) the ATM address interrogation request to all terminals. The server notifies the originating terminal of an ATM address obtained by an answer in response to this interrogation request and registers the ATM address in the ATM address table.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: October 3, 2006
    Assignee: Fujitsu Limited
    Inventor: Kazuo Sakagawa