Patents by Inventor Genichi Ishii

Genichi Ishii 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: 6061389
    Abstract: A frequency hopping communication system having a plurality of wireless mobile stations and at least one base station. Each wireless mobile station is operated to communicate according to a communication frame format generated by a base station. The system performing slow frequency hopping by keeping a frequency hopping interval within each frame. The hopping pattern of a frequency is designated at a field located at the tail of each communication frame by the base station.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: May 9, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Tomoaki Ishifuji, Eiichi Amada, Yoshihiro Takiyasu, Genichi Ishii, Hidehiko Jusa, Shuichi Adachi
  • Patent number: 5862142
    Abstract: In a wireless communication system having a plurality of base stations connected through a control line and a plurality of mobile terminals, one of base stations (a master base station) informs a carrier frequency hop timing to the other base stations (slave base stations) through the control line. Each slave base station generates a wireless communication frame used inside of each cell and switches the carrier frequency of the wireless communication frame in synchronous to the timing indicated by the master base station. Each movable terminal receives an identifier of a frequency hopping sequence from a control information field of the wireless communication frame, hops to one carrier frequency selected among a frequency hopping sequence corresponding to this identifier, and transmit or receive the data through the field following the control information field of the wireless communication frame.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: January 19, 1999
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Takiyasu, Eiichi Amada, Tomoaki Ishifuji, Genichi Ishii, Hidehiko Jusa, Shuichi Adachi
  • Patent number: 5655219
    Abstract: A wireless network is provided for restricting the number of mobile terminal devices which are managed by the base station device for wireless communication with one another. The base station device has a mobile terminal confirming database for registering mobile terminal devices allowed to be subscribers to the wireless network, and a mobile terminal managing database for registering presently-managed mobile terminal devices. The wireless transfer request from one of the mobile terminal devices is tested to determine whether the request-issuing mobile terminal device is one of the subscribers. If the request is accepted, then the identification of the request-issuing mobile terminal device is registered into the managing database.
    Type: Grant
    Filed: March 4, 1994
    Date of Patent: August 5, 1997
    Assignee: Hitachi, Ltd.
    Inventors: Hidehiko Jusa, Eiichi Amada, Yoshihiro Takiyasu, Tomoaki Ishifuji, Genichi Ishii, Shuichi Adachi
  • Patent number: 5559804
    Abstract: A wireless communication system includes a plurality of wireless terminals and a base station for periodically generating a fixed-length communication frame composed of an information field which includes a plurality of information slots, and first and second control fields which are arranged preceding the information field and each of which includes a plurality of time slots. Each time slot of the first control field of each communication frame is used for allowing the base station to send control data for designating a terminal which is to make the transmission or reception of data in one information slot of the information field, and each time slot of the second control field thereof is used for allowing one wireless terminal to send control data indicating a requirement for assignment of an information slot for data transmission.
    Type: Grant
    Filed: April 21, 1994
    Date of Patent: September 24, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Eiichi Amada, Yoshihiro Takiyasu, Tomoaki Ishifuji, Genichi Ishii, Hidehiko Jusa, Shuichi Adachi
  • Patent number: 5537414
    Abstract: In a communication system having a base station for controlling a transmission right and a plurality of substations, a substation having data to be transmitted transmits the number of necessary fragments and its address to a request field of a communication frame. The base station uses a plurality pair of fragment slots and reply slots following the request field in the communication frame to transmit an address of a substation permitted to transmit data, to each fragment slot. The substation permitted to transmit data transmits the address of a destination substation and the data to a predetermined field following the address in one fragment slot. The destination station transmits a reply signal indicating the reception state of the data to the reply slot paired with the fragment slot.
    Type: Grant
    Filed: July 7, 1993
    Date of Patent: July 16, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihiro Takiyasu, Eiichi Amada, Hidehiko Jusa, Tomoaki Ishifuji, Shuichi Adachi, Genichi Ishii