Patents by Inventor Shiro Mazawa

Shiro Mazawa 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: 20090005054
    Abstract: A call connection request from an access terminal is suppressed in a state in which the base station judges that the call connection is impossible, thereby suppressing a waste of the wireless band and the generation of noise. A BCMCS management block of an access point receives information indicating whether there is an allocable channel, from a channel management block of the access point, and information indicating whether the start of QoS can be accepted, from a QoS acceptance determination block of the access point, and the BCMCS management block distributes the information to the access terminal. Accordingly, the access point can inform the access terminal that it is not serviceable before channel allocation is attempted.
    Type: Application
    Filed: April 23, 2008
    Publication date: January 1, 2009
    Inventors: Takanori Moritomo, Yosuke Takahashi, Shiro Mazawa, Yusuke Takemichi
  • Publication number: 20080242303
    Abstract: In a radio communication system in which sequence numbers of radio packets transmitted to first and second radio base stations are managed independently to perform hand-off, when the hand-off is performed while a plurality of fragmented radio packets are transmitted, a mobile device applies sequence numbers of radio packets managed by the first radio base station after the hand-off is performed and applies sequence numbers of radio packets managed by the second radio base station after completion of transmission of the plurality of radio packets. The radio base station managing radio packets is identified on the basis of the sequence numbers managed in each base station upon restoration and data is restored.
    Type: Application
    Filed: January 31, 2008
    Publication date: October 2, 2008
    Inventors: Yosuke TAKAHASHI, Akihiko Yoshida, Daigo Takayanagi, Shiro Mazawa
  • Publication number: 20080205361
    Abstract: The present invention provides a wireless communication system and a terminal. A base station includes means that notifies terminals of an intensity of a received interference power. The terminal includes means that controls a transmission power for transmitting data to the base station, which is one of base stations and to which data is to be transmitted, by referencing an intensity of interference power (OSI) notified from base stations to which data is not to be transmitted. The means that controls a transmission power calculates a decision value for increasing/decreasing the transmission power, wherein the decision value is variable according to the current transmission power of the terminal and propagation attenuations between the terminal and the base stations to which data is not to be transmitted, and variably controls the amount of transmission power increase/decrease according to the decision value for increasing/decreasing a transmission power.
    Type: Application
    Filed: August 23, 2007
    Publication date: August 28, 2008
    Inventors: Keisuke Takeuchi, Toshiyuki Saito, Rintaro Katayama, Shiro Mazawa, Akihiko Yoshida
  • 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: 20080146238
    Abstract: Since the OFDM communication method does not select whether plural sectors use a same terminal as a transmission destination, or always use it as a transmission destination, giving a preference to system throughput deteriorates channel quality of a terminal in a sector boundary, while increasing channel quality in sector boundaries greatly deteriorates system throughput. In a base station, when a sector transmits to a terminal in the front of a beam, only the sector performs the transmission, and when transmission is made to a terminal in a sector boundary off the direction of the beam, a different sector transmits to the same terminal using a same hopping pattern. Thereby, tradeoff between the channel quality of the terminal in a sector boundary and deterioration in system throughput can be minimized.
    Type: Application
    Filed: August 23, 2007
    Publication date: June 19, 2008
    Inventors: Toshiyuki Saito, Rintaro Katayama, Akihiko Yoshida, Shiro Mazawa
  • Publication number: 20080119181
    Abstract: A radio base station, a radio communication terminal, and a radio communication system that can efficiently utilize broadband resources even if many packets of different sizes and different QoS requirements are mixed when sent and received. When a data transmission request is sent from a radio terminal to a base station, at least one of a data transmission duration time, a transmission data transmission interval, and an expiration time is included in the data transmission request. The base station receives data transmission requests from multiple radio terminals, schedules the data transmission requests from multiple radio terminals, assigns bandwidths to the multiple radio terminals based on the duration time, transmission interval, and expiration time included in each of the data transmission requests and continues the assignment of bandwidths to the radio terminals during the duration time based on the received duration time.
    Type: Application
    Filed: August 16, 2007
    Publication date: May 22, 2008
    Inventors: Tomohito Suzuki, Akihiko Yoshida, Toshiyuki Saito, Shiro Mazawa
  • Publication number: 20080076408
    Abstract: A wireless communications system, a terminal, and a base station that, when a terminal has not transmitted data for a predetermined period of time, suppress the transmission power, used when the terminal starts data transmission, by performing transmission power control that makes it easy for the terminal to decrease, or difficult for the terminal to increase, the transmission T2P or that, when a terminal that has not transmitted data for a predetermined period of time requests a sector to assign resources for data transmission, suppress the transmission power, used when the terminal starts data transmission, by transmitting a resource assignment message from the sector to the terminal to instruct the terminal to decrease the transmission power when the terminal starts data transmission.
    Type: Application
    Filed: September 7, 2007
    Publication date: March 27, 2008
    Inventors: Rintaro Katayama, Toshiyuki Saito, Shiro Mazawa, Daigo Takayanagi
  • Publication number: 20080057970
    Abstract: In a wireless communications system operating according to CDMA or the like, when one terminal simultaneously performs communication using multiple wireless resources (e.g., multiple carriers), there was a problem that when it was attempted to guarantee network mobility by the same soft handoff system as in the case where communication was performed using only one wireless resource, efficiency suffered from the viewpoint of network forwarding load, processing load and wireless resource occupancy time. Soft handoff termination is judged and soft handoff is forcibly terminated according to whether or not the data rate obtained for all resources on the network side satisfies a requested rate, based on a reception state notification from a terminal concerning wireless resources.
    Type: Application
    Filed: July 3, 2007
    Publication date: March 6, 2008
    Inventors: May Takada, Yosuke Takahashi, Shiro Mazawa, Rintaro Katayama
  • Publication number: 20070211665
    Abstract: A transmission area is specified flexibly in accordance with the contents of a flow. An area identification number (SHOG) is specified for each interlaced stream of wireless base stations. The same flow is sent at the same timing (or substantially at the same timing) in the interlaced stream specified for the same SHOG. A wireless terminal determines a neighbor sector or a neighbor wireless base station sending the same flow, in accordance with information given from the wireless base stations, and receives and combines the flows.
    Type: Application
    Filed: October 12, 2006
    Publication date: September 13, 2007
    Inventors: Akihiko Yoshida, Shiro Mazawa, Yosuke Takahashi, Daigo Takayanagi
  • Patent number: 7254160
    Abstract: A radio receiver handles a transmitted Walsh sequence having a code length of “m” as a two-dimensional array of “a” rows and “b” columns, and performs a fast Hadamard transform process having a code length of “a” in the row direction. The absolute values of the results are added in the column direction, and a Walsh number having the maximum receiving power is selected to determine a Walsh sequence having a code length of “a.” Then, only the identified column is extracted, and a fast Hadamard transform process having a code length of “b” is applied in the column direction.
    Type: Grant
    Filed: February 12, 2003
    Date of Patent: August 7, 2007
    Assignee: Hitachi Communication Technologies, Ltd.
    Inventors: Kiyoshi Kawamoto, Manabu Kawabe, Shiro Mazawa, Tomoyuki Ono
  • Publication number: 20070086379
    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: Application
    Filed: June 28, 2006
    Publication date: April 19, 2007
    Inventors: Daigo Takayanagi, Kiyoshi Kawamoto, Shiro Mazawa
  • Publication number: 20060291662
    Abstract: A decryption key for decrypting data from an access node is distributed to an access terminal intending to receive the data. An authentication unit receives a message for terminal authentication including a terminal identifier from the terminal and authenticates the terminal. The authentication unit refers to a content registration table having stored in advance the content type of a content which the terminal can receive, in association with the terminal identifier, according to the received terminal identifier to obtain a corresponding content type. The authentication unit refers to a decryption data base having stored in advance a decryption key and its valid period in association with a content type, according to the obtained content type to obtain a corresponding decryption key and valid period. The authentication unit sends an authentication result and the decryption key and valid period to the terminal or to a packet control unit.
    Type: Application
    Filed: June 2, 2006
    Publication date: December 28, 2006
    Inventors: Yosuke Takahashi, Shiro Mazawa, Akihiko Yoshida, Daigo Takayanagi
  • Patent number: 7126924
    Abstract: In data communication using radio communication, an inactivity timer value is changed according to various states, so that an unused time of a communication channel in a non-communication time is decreased, and channel use efficiency is raised. A unit for judging an application of packet data to be transmitted and received by a radio base station 408/a radio base station controller 405 is provided, or an inactivity timer value is set through a port number in TCP/UDP header and a traffic pattern and according to a communication content, and the set inactivity timer value is used to control a change from a connected state to a dormant state.
    Type: Grant
    Filed: March 6, 2002
    Date of Patent: October 24, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Masayasu Suzuki, Manabu Yoshimura, Shiro Mazawa, Hideo Aoe, Arata Nakagoshi
  • Publication number: 20060221963
    Abstract: A master station surely and quickly transmits identical information to plural terminals while controlling consumption of a transmission capacity. First, the master station determines the number of times of multicast transmission from the master station to slave stations. The master station notifies the slave stations of the number of times of multicast transmission determined. Subsequently, the master station transmits information to the slave stations in multicast the determined number of times of multicast transmission. After receiving the information from the master station the number of times of multicast transmission notified, a slave station identifies lacking information in information to be received. The slave station transmits an identifier of the lacking information to the master station. The master station receives the identifier of the lacking information from the slave station and retransmits information corresponding to the identifier of the lacking information to the slave station in unicast.
    Type: Application
    Filed: February 14, 2006
    Publication date: October 5, 2006
    Inventors: Daigo Takayanagi, Shiro Mazawa, Yosuke Takahashi, Akihiko Yoshida
  • Patent number: 7100104
    Abstract: An error correction decoding unit performs error correction decoding of an inputted data series. A first memory is written with the data series subjected to error correction decoding by the error correction decoding unit. When the data series undergoing error correction decoding is written to the first memory, an address generator supplies write addresses and when the data series written to the first memory is read out of the first memory at random, the address generator supplies random read addresses.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: August 29, 2006
    Inventors: Yukio Yamamoto, Shiro Mazawa, Takao Inoue
  • Patent number: 7039425
    Abstract: A terminal usage limiting apparatus for limiting the use of a portable telephone in a specific predetermined area. The terminal usage limiting apparatus 105 is installed to provide service to mobile terminals 101 in a usage limiting area 108. The terminal usage limiting apparatus 105 outputs control signals as a base station and additional usage limit messages. The terminal usage limiting apparatus 105 enables a mobile terminal 101 in the usage limiting area 108 to recognize the apparatus 105 as a base station so that the mobile terminal is switched from the base station to the apparatus 105. As a result, the mobile terminal 101 receives a usage limit message from the apparatus 105. Thus, the mobile terminal 101 enters into a predetermined operation limit mode where call originations are restricted. In addition, in this mode, the mobile terminal 101 receives control messages from the terminal usage limiting apparatus, and the control message includes a long code mask corresponding to the apparatus 105.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: May 2, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Shiro Mazawa, Atsushi Teshima, Kazuhiro Sasame, Yoshitaka Iida
  • Publication number: 20050288025
    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: January 19, 2005
    Publication date: December 29, 2005
    Applicant: Hitachi Communication Technologies, Ltd.
    Inventors: Akihiko Yoshida, Shiro Mazawa, Kiyoshi Kawamoto, Yosuke Takahashi, Keiji Usuba