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).

  • Publication number: 20070201364
    Abstract: A wireless communication apparatus is disclosed. A transmitting device transmits a first aggregation frame in which first transmission data frames are aggregated. A measuring device measures a number value of retransmission of each of the first transmission data frames. A storage stores a limiting value of the number value of retransmission. A determination device determines whether the number value of retransmission of each of the first transmission data frames exceeds the limiting value. A transmission buffer buffers the first transmission data frames for which it is determined that the number value of retransmission does not exceed the limiting value, and discards the first transmission data frames for which it is determined that the number value of retransmission exceeds the limiting value, of the first transmission data frames. A retransmitting device retransmits the first aggregation frame in which the first transmission data frames buffered in the transmission buffer are aggregated.
    Type: Application
    Filed: May 4, 2007
    Publication date: August 30, 2007
    Inventors: Tetsu NAKAJIMA, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Yasuyuki Nishibayashi
  • Patent number: 7236782
    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: Grant
    Filed: June 13, 2005
    Date of Patent: June 26, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Publication number: 20070060159
    Abstract: A radio communication apparatus includes an acquiring device which acquires information required to determine a ratio between a first period length making a radio communication by using either of two first channels each having a first bandwidth and a second period length making a radio communication by using a second channel having a second bandwidth wider than the first bandwidth. The second channel is overlapping with the two first channels. A determining device determines the ratio on the basis of the information, thereby determines the first period length and the second period length. Accordingly, a radio communication by using the first channel within the first period length and a radio communication by using the second channel within the second period length are performed.
    Type: Application
    Filed: March 22, 2006
    Publication date: March 15, 2007
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai
  • Patent number: 7174161
    Abstract: A radio communication apparatus which can communicate with a base station in radio communication, comprising: an antenna; a reception processing unit which receives a signal transmitted from the base station via the antenna; an indication signal processing unit which processes an indication signal including information on the base station, the indication signal being transmitted from the base station periodically; and an authentication processing unit which performs authentication processing with the base station to establish communication connection between the base station and the radio communication apparatus, wherein, when the reception processing unit and the indication signal processing unit are in ON state, unitthe authentication processing unit is in OFF state.unitunit.
    Type: Grant
    Filed: July 27, 2004
    Date of Patent: February 6, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tetsu Nakajima, Tomoko Adachi, Kiyoshi Toshimitsu, Takafumi Sakamoto
  • Publication number: 20070014237
    Abstract: A communication apparatus generates a single physical frame including a plurality of MAC frames, and transmits the physical frame. The physical frame has variable-length bitmap information comprising bits corresponding to the plurality of MAC frames, respectively, and length information of the bitmap information.
    Type: Application
    Filed: September 25, 2006
    Publication date: January 18, 2007
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Daisuke Takeda
  • Publication number: 20060221879
    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: Application
    Filed: March 22, 2006
    Publication date: October 5, 2006
    Inventors: Tetsu Nakajima, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Kiyoshi Toshimitsu
  • Publication number: 20060114928
    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: Application
    Filed: August 11, 2005
    Publication date: June 1, 2006
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Publication number: 20060092871
    Abstract: A physical frame is generated and transmitted to a destination terminal. In this physical frame, one of a data frame, an acknowledgement frame, and an acknowledgement request frame, and a transmission permission frame which is used in place of a normal Ack frame associated with a delayed Block Ack, and permits the destination terminal to perform piggyback transmission, are aggregated.
    Type: Application
    Filed: August 11, 2005
    Publication date: May 4, 2006
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Tomoya Tandai, Yoriko Utsunomiya
  • Publication number: 20060083233
    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: August 11, 2005
    Publication date: April 20, 2006
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20060084461
    Abstract: A wireless communication apparatus includes an M-number of (M is an integer of 2 or more) receiving portions connected to respective antennas, a frame analyzing section configured to analyze a reception signal received by the M-number of receiving portions, and a selecting section configured to select a receiving portion to be in service from the M-number of receiving portions. The selecting section selects a P-number of (P is an integer of from 0 to M) receiving portions from the M-number of receiving portions, based on an analysis result obtained by the frame analyzing section.
    Type: Application
    Filed: October 14, 2005
    Publication date: April 20, 2006
    Inventors: Masahiro Sekiya, Kiyoshi Toshimitsu, Tetsu Nakajima, Katsuya Nounin, Tsuguhide Aoki, Tomoya Tandai, Tomoko Adachi, Daisuke Takeda
  • Publication number: 20060034174
    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: August 10, 2005
    Publication date: February 16, 2006
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20060013184
    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: Application
    Filed: June 23, 2005
    Publication date: January 19, 2006
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Publication number: 20050282551
    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: Application
    Filed: June 16, 2005
    Publication date: December 22, 2005
    Inventors: Tomoya Tandai, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Masahiro Takagi, Daisuke Takeda, Kazumi Sato
  • Publication number: 20050277411
    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: June 13, 2005
    Publication date: December 15, 2005
    Inventors: Yoriko Utsunomiya, Tomoko Adachi, Masahiro Takagi, Tetsu Nakajima, Tomoya Tandai, Yasuyuki Nishibayashi
  • Publication number: 20050265298
    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: May 26, 2005
    Publication date: December 1, 2005
    Inventors: Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi, Daisuke Takeda
  • Publication number: 20050265302
    Abstract: A wireless communication apparatus includes 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: May 26, 2005
    Publication date: December 1, 2005
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tomoya Tandai, Tetsu Nakajima, Yoriko Utsunomiya
  • Publication number: 20050265297
    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: Application
    Filed: May 24, 2005
    Publication date: December 1, 2005
    Inventors: Tetsu Nakajima, Tomoko Adachi, Masahiro Takagi, Tomoya Tandai, Yoriko Utsunomiya, Yasuyuki Nishibayashi
  • Publication number: 20050238016
    Abstract: A communication apparatus generates a single physical frame including a plurality of MAC frames, and transmits the physical frame. The physical frame has variable-length bitmap information comprising bits corresponding to the plurality of MAC frames, respectively, and length information of the bitmap information.
    Type: Application
    Filed: April 21, 2005
    Publication date: October 27, 2005
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Daisuke Takeda
  • Publication number: 20050220145
    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: Application
    Filed: March 24, 2005
    Publication date: October 6, 2005
    Inventors: Yasuyuki Nishibayashi, Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Tomoya Tandai
  • Publication number: 20050208956
    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: Application
    Filed: March 4, 2005
    Publication date: September 22, 2005
    Inventors: Masahiro Takagi, Tomoko Adachi, Tetsu Nakajima, Yoriko Utsunomiya, Yasuyuki Nishibayashi