Patents by Inventor Tetsu Nakajima

Tetsu Nakajima 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: 7701962
    Abstract: A wireless communication apparatus for performing wireless communication using a first channel having a first frequency bandwidth, and a second channel formed of both the first channel and a second communication channel, the second communication channel having a frequency bandwidth equal to the first frequency bandwidth. A first generation of a first declaration frame for declaring occupation of the first channel for a specified period, and a second generation of a second declaration frame for declaring occupation of the second communication channel for a specified period after the first declaration frame are generated and transmitted. Transmission timings are set so that the first and second declaration frames are transmitted at the highest priority of all the other frames.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: April 20, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Patent number: 7697491
    Abstract: A wireless communication apparatus includes a transmitting device configured to transmit burst data of a plurality of transmission data, a receiving device configured to receive an acknowledgement status of the burst data transmitted by the transmitting device, a retransmitting device configured to control the transmitting device to retransmit any of the plurality of transmission data contained in the burst data, in accordance with the acknowledgement status received by the receiving device, and a retransmission limiting device configured to limit the retransmission for each frame exchange sequence of the burst data.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: April 13, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tetsu Nakajima, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Yasuyuki Nishibayashi
  • Patent number: 7697561
    Abstract: A communication apparatus includes a frame generating device configured to generate a physical frame containing, of a plurality of MAC frames to be transmitted, a MAC frame which requires acknowledgement indicating that the frame is received by a receiving side, a MAC frame which does not require the acknowledgement, and identification information which indicates necessity/unnecessity of acknowledgement for each MAC frame depending on whether each MAC frame requires acknowledgement, and a transmitting device configured to transmit the physical frame generated by the frame generating device.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: April 13, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20100074277
    Abstract: A generation device generates a frame to be transmitted to a destination communication apparatus. The frame includes a first separation field, a first MAC protocol data unit (MPDU) following the first separation field, a second separation field following the first MPDU, a third separation field following the second separation field, and a third MPDU following the third separation field. The second separation field includes length information set to a value of zero to indicate no second MPDU directly follows the second separation field. The first MPDU includes a first MAC header, a first data field, and a first frame check sequence (FCS). The first FCS is for detecting an error occurred in at least the first data field. The third MPDU includes a third MAC header, a third data field, and a third FCS. The third FCS is for detecting an error occurred in at least the third data field.
    Type: Application
    Filed: November 27, 2009
    Publication date: March 25, 2010
    Inventors: Yasuyuki NISHIBAYASHI, Masahiro TAKAGI, Tomoko ADACHI, Tetsu NAKAJIMA, Yoriko UTSUNOMIYA, Tomoya TANDAI
  • Patent number: 7680148
    Abstract: A communication apparatus includes a receiving device configured to receive one physical frame in which a plurality of MAC frames are aggregated. This physical frame includes one acknowledgement request frame for the plurality of MAC frames. The apparatus includes an acknowledgement frame forming device configured to form an acknowledgement frame representing reception statuses of the plurality of MAC frames in response to the acknowledgement request frame. The apparatus also includes a transmitting device configured to transmit the acknowledgement frame. This acknowledgement frame includes a compressed acknowledgement frame representing an acknowledgement bitmap having a size equal to a maximum number of MSDUs (MAC Service Data Units) when one MPDU (MAC Protocol Data Unit) corresponds to one MSDU.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: March 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20100046540
    Abstract: A communication apparatus includes a receiving device configured to receive one physical frame in which a plurality of MAC frames are aggregated. This physical frame includes one acknowledgement request frame for the plurality of MAC frames. The apparatus includes an acknowledgement frame forming device configured to form an acknowledgement frame representing reception statuses of the plurality of MAC frames in response to the acknowledgement request frame. The apparatus also includes a transmitting device configured to transmit the acknowledgement frame. This acknowledgement frame includes a compressed acknowledgement frame representing an acknowledgement bitmap having a size equal to a maximum number of MSDUs (MAC Service Data Units) when one MPDU (MAC Protocol Data Unit) corresponds to one MSDU.
    Type: Application
    Filed: October 27, 2009
    Publication date: February 25, 2010
    Inventors: Yasuyuki NISHIBAYASHI, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20100046437
    Abstract: A communication apparatus includes a receiving device configured to receive one physical frame in which a plurality of MAC frames are aggregated. This physical frame includes one acknowledgement request frame for the plurality of MAC frames. The apparatus includes an acknowledgement frame forming device configured to form an acknowledgement frame representing reception statuses of the plurality of MAC frames in response to the acknowledgement request frame. The apparatus also includes a transmitting device configured to transmit the acknowledgement frame. This acknowledgement frame includes a compressed acknowledgement frame representing an acknowledgement bitmap having a size equal to a maximum number of MSDUs (MAC Service Data Units) when one MPDU (MAC Protocol Data Unit) corresponds to one MSDU.
    Type: Application
    Filed: October 27, 2009
    Publication date: February 25, 2010
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Patent number: 7664129
    Abstract: A wireless communication apparatus includes a carrier sense device which determines whether or not the first channel satisfies a specific condition of the determination of an idle state, and an occupation/release control device which performs control to make the first physical layer protocol processing device generate and transmit a first frame which declares that the first channel will be occupied for a first predetermined period by virtual carrier sense, when the specific condition of the determination of the idle state is satisfied, and perform control to make the second physical layer protocol processing device generate and transmit a second frame which declares that the second channel will be occupied for a second predetermined period by virtual carrier sense.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: February 16, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi
  • Patent number: 7650559
    Abstract: A communication apparatus includes a physical frame generating device configured to generate a single physical frame which includes a plurality of media access control frames having different destinations and in which frames, of the media access control frames, which have the same destination are consecutively arranged, and a transmitting device configured to transmit the physical frame generated by the physical frame generating device.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: January 19, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Tomoya Tandai
  • Publication number: 20100002646
    Abstract: A communication apparatus includes a receiving device configured to receive a physical frame in which a plurality of MAC frames, each having a sequence number, are aggregated. A reception buffer which stores MAC frames of the physical frame received by the receiving device. A determination device determines whether or not the first MAC frame in the physical frame received by the receiving device has been successfully received. A reception buffer management device determines, when the first MAC frame has been successfully received, a MAC frame to be forwarded to an upper layer, on the basis of the sequence number of the first MAC frame, and extracts the MAC frame from the reception buffer.
    Type: Application
    Filed: September 11, 2009
    Publication date: January 7, 2010
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagai, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Patent number: 7626968
    Abstract: A wireless communication system includes first and second wireless terminals capable of performing transmission by at least one of a first transmission scheme and a second transmission scheme. The first wireless terminal performs transmission of a first frame to the second wireless terminal by using the second transmission scheme. The second wireless terminal communicates with the first wireless terminal to notify the first wireless terminal of information associated with a status of the reception of the first frame transmitted from the first wireless terminal by using the first transmission scheme.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: December 1, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Daisuke Takeda
  • Publication number: 20090196364
    Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.
    Type: Application
    Filed: December 24, 2008
    Publication date: August 6, 2009
    Inventors: Tetsu Nakajima, Tomoko Adachi, Yoriko Utsunomiya, Tomoya Tandai, Masahiro Takagi
  • Patent number: 7558225
    Abstract: A radio base station apparatus used in a radio communication system in which an initiator holds a transmission opportunity (TXOP) period in a frame exchange sequence and a responder responds to the initiator in the frame exchange sequence is disclosed. The apparatus includes a setting device which sets a ratio between a first period necessary for transmitting a first frame from the initiator to the responder and a second period necessary for transmitting a second frame from the responder to the initiator. The apparatus also includes a calculation device which calculates the first period to be used by the initiator and the second period to be used by the responder, on the basis of the transmission opportunity period and of the ratio which is set.
    Type: Grant
    Filed: March 22, 2006
    Date of Patent: July 7, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tetsu Nakajima, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Kiyoshi Toshimitsu
  • Publication number: 20090022132
    Abstract: A wireless communication system includes first and second wireless terminals capable of performing transmission by at least one of a first transmission scheme and a second transmission scheme. The first wireless terminal performs transmission of a first frame to the second wireless terminal by using the second transmission scheme. The second wireless terminal communicates with the first wireless terminal to notify the first wireless terminal of information associated with a status of the reception of the first frame transmitted from the first wireless terminal by using the first transmission scheme.
    Type: Application
    Filed: September 24, 2008
    Publication date: January 22, 2009
    Inventors: Tomoko ADACHI, Masahiro Takagi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Daisuke Takeda
  • Patent number: 7430195
    Abstract: A wireless communication system having wireless terminal stations to perform direct communication without passing through a wireless base station. This system includes a wireless communication device which performs either a first wireless communication using a first channel having a first frequency band or the second wireless communication using a second channel having a second frequency band with a bandwidth greater than that of the first frequency band. This system also includes a generation device which generates a switching control frame to control switching between a communication period by the first wireless communication and a communication period by the second wireless communication, and a communication control device which controls the wireless communication device so as to transmit the switching control frame. A wireless terminal station is selected as a temporal central control station having a switching control right to control switching between the first and second wireless communications.
    Type: Grant
    Filed: June 23, 2005
    Date of Patent: September 30, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Publication number: 20080181251
    Abstract: A communication apparatus includes a receiving device configured to receive one physical frame in which a plurality of MAC frames are aggregated. This physical frame includes one acknowledgement request frame for the plurality of MAC frames. The apparatus includes an acknowledgement frame forming device configured to form an acknowledgement frame representing reception statuses of the plurality of MAC frames in response to the acknowledgement request frame. The apparatus also includes a transmitting device configured to transmit the acknowledgement frame. This acknowledgement frame includes a compressed acknowledgement frame representing an acknowledgement bitmap having a size equal to a maximum number of MSDUs (MAC Service Data Units) when one MPDU (MAC Protocol Data Unit) corresponds to one MSDU.
    Type: Application
    Filed: March 25, 2008
    Publication date: July 31, 2008
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20080165713
    Abstract: A wireless communication apparatus including a main queue to store MAC frames, a plurality of subqueues related to the main queue and used to control retransmission of the MAC frame, each of the subqueues having different priority for transmission of the MAC frame, respectively, an extracting device configured to extract the MAC frame from the main queue on the basis of a destination and the priority, and distribute the extracted MAC frame to one of the plurality of subqueues for each priority, and an aggregating device configured to extract MAC frames from the plurality of subqueues to form a MAC super frame.
    Type: Application
    Filed: March 14, 2008
    Publication date: July 10, 2008
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Patent number: 7343162
    Abstract: In a wireless communication system having a wireless base station, wireless terminal stations belonging to a first group which performs wireless communication while sharing different frequency channels, and wireless terminal stations belonging to a second group which performs wireless communication by using one frequency channel, a first communication period and a second communication period is alternately repeated. In this system, a wireless terminal station belonging to the first or the second group communicates with the wireless base station by using a first frequency channel in the first communication period. Direct communication between two wireless terminal stations belonging to the first group by using a second frequency channel without through the wireless base station is performed in the first communication period. Then, a wireless terminal station belonging to the first group communicates with the wireless base station by using both the first and the second frequency channels.
    Type: Grant
    Filed: June 16, 2005
    Date of Patent: March 11, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomoya Tandai, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Masahiro Takagi, Daisuke Takeda, Kazumi Sato
  • Publication number: 20080002615
    Abstract: A wireless communication apparatus performs bi-directional communication with an initiator. The apparatus is allocated an allocation period for data transmission from the initiator. The apparatus includes means for generating a first physical frame including an acknowledgement frame with respect to data received from the initiator, and generating a second physical frame in which a plurality of transmission data frames addressed to the initiator are aggregated. The apparatus also includes means for transmitting the first physical frame at a first transmission rate and the second physical frame at a second transmission rate, during the allocation period.
    Type: Application
    Filed: August 30, 2007
    Publication date: January 3, 2008
    Inventors: Tetsu Nakajima, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Toshihisa Nabetani
  • Publication number: 20070232303
    Abstract: A wireless communication apparatus for performing wireless communication using at least one of the first channel having the first frequency band, and the second channel having the second frequency band which is wider than the first frequency band includes a channel search device which executes the first channel search for the bandwidth of the first frequency band and the second channel search for the bandwidth of the second frequency band, and obtains a search result indicating an idle channel, and a determination device which determines a channel to be used on the basis of the search result obtained by the channel search device.
    Type: Application
    Filed: May 21, 2007
    Publication date: October 4, 2007
    Inventors: Yoriko UTSUNOMIYA, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi