Patents by Inventor Kiyoshi Kawamoto

Kiyoshi Kawamoto 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: 8358637
    Abstract: A method for preventing or correcting the imbalance in load among interlaces in communications based on CDMA whereby communication resources are allocated to the respective interlaces through an interlacing scheme. A base station measures load information on an interlace-by-interlace basis, and notifies the same to a terminal while the terminal filters the load information to utilize the same for making a decision on transmission timing. Or the base station notifies the terminal of load information on plural transmission timings, and the terminal selects an adequate transmission timing to be then utilized. Otherwise, the base station presents at least two probabilities of transition between interlaces, urging the terminal to update an interlace (transmission timing) on a probabilistic basis.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: January 22, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Toshiyuki Saito, Kiyoshi Kawamoto, Mikio Kuwahara
  • Patent number: 8116263
    Abstract: An AN (Access Network) controlled by a communication control apparatus and communicating with a AT Access Terminal), wherein the AN receives control information including information for allocating communication information from the communication control apparatus, and the AN transmits transmission cycle information for transmitting the communication information in a predetermined transmission cycle to the AT and allocates the communication information in the predetermined transmission cycle based on the control information received from the communication control apparatus to send the communication information to the AT.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: February 14, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Patent number: 8094600
    Abstract: A radio communication system including: ANs (Access Networks) for wirelessly communicating with an AT (Access Terminal); and a communication control apparatus for controlling the AN, wherein the communication control apparatus includes: a control unit for sending transmission cycle information and control information to the AN, and wherein the AN includes: a memory for storing information necessary for transmitting the communication information to the AT; a control unit for transmitting the transmission cycle information received from the communication control apparatus to the AT, calculating a transmission slot number necessary for sending the communication information in the transmission cycle, determining a transmission timing indicating a period in the predetermined transmission cycle allocated for the communication information, and transmitting the communication information in the determined transmission timing to the AT.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: January 10, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Patent number: 8085735
    Abstract: A wireless communication device for a communication system including data channels and control channels is disclosed. This device includes a receive section for receiving signals including data signals sent over the data channels, and control signals sent over control channels, the control signal corresponding to the data signals, a control channel demodulator for demodulating the control signals indicating at least one of the packet size and modulation method, a memory for accumulating the receive signals during the demodulation of the control signals, and a data channel demodulator for loading the receive signal from the memory, and demodulating the data signal according to the indicated at least one of the packet size and modulation method determined based on the demodulated control signals.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: December 27, 2011
    Assignee: Hitachi, Ltd.
    Inventors: May Suzuki, Kiyoshi Kawamoto, Joichi Saito
  • Patent number: 8073381
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Grant
    Filed: September 23, 2008
    Date of Patent: December 6, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Patent number: 8036652
    Abstract: In a case where reception power in a radio access point is high by external noise, the normalcy of the radio access point is tested. In order to judge the normalcy of the radio characteristic of the radio access point, a test is performed through the calling connection between a testing access terminal in the radio access point and a predetermined device. An RSSI is measured before and after the transmission of a test signal. When the RSSI exceeds a threshold value, the path loss of a reverse link connected from the radio access point to the testing access terminal is increased by an attenuator. Then, reception power in the testing access terminal decreases. Thus, initial transmission power in accordance with the reception power from the testing access terminal is raised and the calling connection of the testing access terminal can be performed even under the external noise.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: October 11, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoshi Kawamoto, Akihiko Yoshida
  • Patent number: 7996033
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: August 9, 2011
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20110164524
    Abstract: In a case where reception power in a radio access point is high by external noise, the normalcy of the radio access point is tested. In order to judge the normalcy of the radio characteristic of the radio access point, a test is performed through the calling connection between a testing access terminal in the radio access point and a predetermined device. An RSSI is measured before and after the transmission of a test signal. When the RSSI exceeds a threshold value, the path loss of a reverse link connected from the radio access point to the testing access terminal is increased by an attenuator. Then, reception power in the testing access terminal decreases. Thus, initial transmission power in accordance with the reception power from the testing access terminal is raised and the calling connection of the testing access terminal can be performed even under the external noise.
    Type: Application
    Filed: March 16, 2011
    Publication date: July 7, 2011
    Inventors: Kiyoshi Kawamoto, Akihiko Yoshida
  • Patent number: 7912478
    Abstract: Admission control wireless resources including abase station which obtains a down wireless resource available rate based on a down QoS requested bandwidth Bi requested by a terminal i during QoS communication and a data rate Ri which the terminal can receive. A down wireless resource usage rate is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. An up wireless resource available rate is obtained based on ROT of an up channel and a threshold value T1 indicating an allowable upper limit of the ROT. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: March 22, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Daigo Takayanagi, Kiyoshi Kawamoto, Shiro Mazawa
  • Patent number: 7907951
    Abstract: Admission control wireless resources including abase station which obtains a down wireless resource available rate based on a down QoS requested bandwidth Bi requested by a terminal i during QoS communication and a data rate Ri which the terminal can receive. A down wireless resource usage rate is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. An up wireless resource available rate is obtained based on ROT of an up channel and a threshold value T1 indicating an allowable upper limit of the ROT. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: March 15, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Daigo Takayanagi, Kiyoshi Kawamoto, Shiro Mazawa
  • Patent number: 7724724
    Abstract: In order to realize such communication control as to reliably reconstruct communication information transmitted from a plurality of ANs at a plurality of ATs even when a BCMCS flow is added or deleted, a radio communication system includes a transmitter for transmitting control information necessary for the ATs to receive the communication information from a radio communication system at intervals of a predetermined period, and a controller for controlling to transmit a plurality of pieces of communication information to the ATs at intervals of a constant cycle and in synchronism with a transmission period of the control information.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: May 25, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20100103817
    Abstract: Admission control wireless resources including abase station which obtains a down wireless resource available rate based on a down QoS requested bandwidth Bi requested by a terminal i during QoS communication and a data rate Ri which the terminal can receive. A down wireless resource usage rate is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. An up wireless resource available rate is obtained based on ROT of an up channel and a threshold value T1 indicating an allowable upper limit of the ROT. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.
    Type: Application
    Filed: October 22, 2009
    Publication date: April 29, 2010
    Inventors: Daigo TAKAYANAGI, Kiyoshi KAWAMOTO, Shiro MAZAMA
  • Publication number: 20100040013
    Abstract: Admission control wireless resources including abase station which obtains a down wireless resource available rate based on a down QoS requested bandwidth Bi requested by a terminal i during QoS communication and a data rate Ri which the terminal can receive. A down wireless resource usage rate is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. An up wireless resource available rate is obtained based on ROT of an up channel and a threshold value T1 indicating an allowable upper limit of the ROT. The QoS communication is performed on the terminal in which the up and down wireless resource available rates are respectively equal to or more than the up and down wireless resource usage rates.
    Type: Application
    Filed: October 22, 2009
    Publication date: February 18, 2010
    Inventors: Daigo TAKAYANAGI, Kiyoshi Kawamoto, Shiro Mazawa
  • Patent number: 7634278
    Abstract: There is provided admission control in view of wireless resources. A base station 120 obtains a down wireless resource available rate (available rate of slot allocation) based on a down QoS requested bandwidth Bi requested by a terminal i during QoS communication and a data rate Ri which the terminal can receive. A down wireless resource usage rate necessary to ensure the requested bandwidth B is obtained by dividing a down QoS requested bandwidth B requested by the terminal trying to perform QoS communication by the data rate R which the terminal can receive. The base station 120 obtains an up wireless resource available rate based on ROT of an up channel and a threshold value T1 indicating an allowable upper limit of the ROT. Besides, an up wireless resource usage rate necessary to ensure an up requested bandwidth requested by the terminal is obtained.
    Type: Grant
    Filed: June 28, 2006
    Date of Patent: December 15, 2009
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Daigo Takayanagi, Kiyoshi Kawamoto, Shiro Mazawa
  • Publication number: 20090023382
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Application
    Filed: September 23, 2008
    Publication date: January 22, 2009
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko YOSHIDA, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20080181164
    Abstract: A radio communication system including: ANs (Access Networks) for wirelessly communicating with an AT (Access Terminal); and a communication control apparatus for controlling the AN, wherein the communication control apparatus sends transmission cycle information and control information to the AN, and wherein the AN transmits the transmission cycle information received from the communication control apparatus to the AT, allocates the communication information in the predetermined transmission cycle based on the control information received from the communication control apparatus to transmit the communication information to the AT, wherein, if the AN does not need to transmit any of plural pieces of the communication information to the AT for a subject period any longer, the AN uses the subject period to transmit any of other plural pieces of the communication information which is allocated to a next period.
    Type: Application
    Filed: March 26, 2008
    Publication date: July 31, 2008
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20080181193
    Abstract: A radio communication system including: ANs (Access Networks) for wirelessly communicating with an AT (Access Terminal); and a communication control apparatus for controlling the AN, wherein the communication control apparatus includes: a control unit for sending transmission cycle information and control information to the AN, and wherein the AN includes: a memory for storing information necessary for transmitting the communication information to the AT; a control unit for transmitting the transmission cycle information received from the communication control apparatus to the AT, calculating a transmission slot number necessary for sending the communication information in the transmission cycle, determining a transmission timing indicating a period in the predetermined transmission cycle allocated for the communication information, and transmitting the communication information in the determined transmission timing to the AT.
    Type: Application
    Filed: March 26, 2008
    Publication date: July 31, 2008
    Inventors: Akihiko YOSHIDA, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20080182612
    Abstract: A radio communication system includes a grouping unit for grouping a plurality of base stations into a plurality of groups (Soft Handoff Groups) and a determining unit for selecting base stations belonging to one and the same group selected from the groups produced by the grouping unit and for determining the base stations as base stations to send communication packets to an access terminal.
    Type: Application
    Filed: March 31, 2008
    Publication date: July 31, 2008
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20080175218
    Abstract: An AN (Access Network) controlled by a communication control apparatus and communicating with a AT Access Terminal), wherein the AN receives control information including information for allocating communication information from the communication control apparatus, and the AN transmits transmission cycle information for transmitting the communication information in a predetermined transmission cycle to the AT and allocates the communication information in the predetermined transmission cycle based on the control information received from the communication control apparatus to send the communication information to the AT.
    Type: Application
    Filed: October 11, 2007
    Publication date: July 24, 2008
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba
  • Publication number: 20080031144
    Abstract: In a case where reception power in a radio access point is high by external noise, the normalcy of the radio access point is tested. In order to judge the normalcy of the radio characteristic of the radio access point, a test is performed through the calling connection between a testing access terminal in the radio access point and a predetermined device. An RSSI is measured before and after the transmission of a test signal. When the RSSI exceeds a threshold value, the path loss of a reverse link connected from the radio access point to the testing access terminal is increased by an attenuator. Then, reception power in the testing access terminal decreases. Thus, initial transmission power in accordance with the reception power from the testing access terminal is raised and the calling connection of the testing access terminal can be performed even under the external noise.
    Type: Application
    Filed: June 5, 2007
    Publication date: February 7, 2008
    Inventors: Kiyoshi Kawamoto, Akihiko Yoshida