Patents by Inventor Keigo Hasegawa

Keigo Hasegawa 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: 10939253
    Abstract: A plurality of terminal stations that share the same access point are controlled to have communication opportunities on the basis of terminal station groups (e.g., operators). A radio communication system, in which the plurality of terminal stations 102 to 106 is connected to a network via an access point 101, includes an access manager 107 connected to the access point. The access manager includes a user/group manager that manages the plurality of terminal stations in groups, and a radio resource manager that determines the necessity of bandwidth limit on the basis of the communication status of each of the groups and transmit from the access point a control message that allows communication of a particular group among the groups and stops communication of other groups when it is determined that the bandwidth limit is necessary.
    Type: Grant
    Filed: November 15, 2017
    Date of Patent: March 2, 2021
    Assignee: HITACHI KOKUSAI ELECTRIC INC.
    Inventor: Keigo Hasegawa
  • Publication number: 20200382913
    Abstract: A plurality of terminal stations that share the same access point are controlled to have communication opportunities on the basis of terminal station groups (e.g., operators). A radio communication system, in which the plurality of terminal stations 102 to 106 is connected to a network via an access point 101, includes an access manager 107 connected to the access point. The access manager includes a user/group manager that manages the plurality of terminal stations in groups, and a radio resource manager that determines the necessity of bandwidth limit on the basis of the communication status of each of the groups and transmit from the access point a control message that allows communication of a particular group among the groups and stops communication of other groups when it is determined that the bandwidth limit is necessary.
    Type: Application
    Filed: November 15, 2017
    Publication date: December 3, 2020
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventor: KEIGO HASEGAWA
  • Publication number: 20200082056
    Abstract: A machine learning model fraud detection system and fraud detection method wherein a license/model management apparatus: generates a test data-trained model by inputting a pre-trained model and test data associated therewith from a licensor apparatus, carrying out learning using the test data on the pre-trained model; stores the test data-trained model in association with the output values obtained when the test data is executed in the test data-trained model; inputs the associated test data into a user model, executes the model when the user model is inputted from a user apparatus using the test data-trained model; compares the output data from the user model with the stored output values from the test data-trained model and detects the fraud if the resulting error is outside tolerance limits.
    Type: Application
    Filed: April 10, 2018
    Publication date: March 12, 2020
    Inventor: Keigo HASEGAWA
  • Patent number: 10164702
    Abstract: A wireless communication system comprises a mobile communication apparatus, and a terminal device. The mobile communication apparatus comprises a first wireless unit that wirelessly communicates control information to and from the terminal device in a first communication method, and a second wireless unit that wirelessly communicates user information to and from the terminal device in a second communication method that uses a higher frequency band than the first communication method. The terminal device comprises a third wireless unit that performs wireless communication to and from the first wireless unit, and a fourth wireless unit that performs wireless communication to and from the second wireless unit. The mobile communication apparatus or the terminal device determines a timing of wireless communication to be performed between the second wireless unit and the fourth wireless unit by performing wireless communication between the first wireless unit and the third wireless unit.
    Type: Grant
    Filed: February 27, 2015
    Date of Patent: December 25, 2018
    Assignee: Hitachi Kokusai Electric Inc.
    Inventor: Keigo Hasegawa
  • Patent number: 10070406
    Abstract: A method for adjusting a transmission timing of a terminal station, which is performed at a base station in a Time-Division Duplex communication system, is disclosed. The method includes (a) receiving ranging signals or other reference signals, transmitted from a terminal station; (b) determining whether transmission timing at the terminal station is appropriate or not, by referring to the ranging signals transmitted from the terminal station; and (c) transmitting a value for adjusting the transmission timing at the terminal station. The value of the transmission timing is a value of the integral multiples of the timing offset detection capability of the ranging signal, or a value calculated by referring to the received reference signals, which have assigned with a different interval from an interval of the ranging signals.
    Type: Grant
    Filed: September 20, 2016
    Date of Patent: September 4, 2018
    Assignee: Hitachi Kokusai Electric, Inc.
    Inventors: Masayuki Takekawa, Keigo Hasegawa
  • Publication number: 20180049110
    Abstract: A wireless communication system comprises a mobile communication apparatus, and a terminal device. The mobile communication apparatus comprises a first wireless unit that wirelessly communicates control information to and from the terminal device in a first communication method, and a second wireless unit that wirelessly communicates user information to and from the terminal device in a second communication method that uses a higher frequency band than the first communication method. The terminal device comprises a third wireless unit that performs wireless communication to and from the first wireless unit, and a fourth wireless unit that performs wireless communication to and from the second wireless unit. The mobile communication apparatus or the terminal device determines a timing of wireless communication to be performed between the second wireless unit and the fourth wireless unit by performing wireless communication between the first wireless unit and the third wireless unit.
    Type: Application
    Filed: February 27, 2015
    Publication date: February 15, 2018
    Inventor: Keigo HASEGAWA
  • Patent number: 9781719
    Abstract: The present invention introduces a multichannel MAC into a white-space-using system. A base station and a terminal station are each configured from a plurality of wireless communication units and centralized control units thereof. Each of the wireless communication units wirelessly transmits/receives for one channel. The base station operates one or more channels according to white-space-channel status, and is assigned to a terminal station. When operating a plurality of channels, it is possible to select a redundancy mode for assigning data by duplicating the terminal-station data in a plurality of channels, and a high-speed mode for dividing the data and distributing the data among the plurality of channels.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: October 3, 2017
    Assignee: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Keigo Hasegawa, Keat Beng Toh, Masayuki Takekawa, Kei Yanagisawa, Madoka Tanaka
  • Patent number: 9743412
    Abstract: In the wireless communication system, each of a base station 11 and a terminal station 12 obtains its location information, and upon establishment of synchronization, the terminal station 12 transmits a terminal station free channel list and its location information by extremely low power wireless communication, and the base station 11 compares a base station free channel list created based on information from a database 40 with the terminal station free channel list from the terminal station 12, and determines, when there is a common free channel, the free channel as uplink/downlink channels and determines, when there is no common free channel, an uplink channel and a downlink channel as different channels, calculates a base station-terminal station distance from the location information of the base station 11 and the location information of the terminal station 12, and determines terminal station's uplink transmission power based on the distance.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: August 22, 2017
    Assignee: Hitachi Kokusai Electric, Inc.
    Inventors: Kei Yanagisawa, Keigo Hasegawa, Masayuki Takekawa
  • Patent number: 9713171
    Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: July 18, 2017
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Kei Yanagisawa, Masayuki Takekawa, Keigo Hasegawa
  • Patent number: 9661644
    Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.
    Type: Grant
    Filed: March 28, 2014
    Date of Patent: May 23, 2017
    Assignee: Hitachi Kokusai Electric, Inc.
    Inventors: Masayuki Takekawa, Keigo Hasegawa, Kei Yanagisawa
  • Patent number: 9609523
    Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.
    Type: Grant
    Filed: September 10, 2014
    Date of Patent: March 28, 2017
    Assignee: HITACHI KOKUSAI ELECTRIC, INC.
    Inventors: Masayuki Takekawa, Keigo Hasegawa, Kei Yanagisawa, Keat Beng Toh
  • Patent number: 9572076
    Abstract: The present invention provides a wireless communication terminal which can flexibly select a base station according to communication quality and a load status and improve communication quality which a user experiences in a wireless communication system which does not include a handover mechanism and is not notified of availability of radio resources from each base station.
    Type: Grant
    Filed: June 30, 2016
    Date of Patent: February 14, 2017
    Assignee: HITACHI KOKUSAI ELECTRIC, INC.
    Inventor: Keigo Hasegawa
  • Publication number: 20170013582
    Abstract: A method for adjusting a transmission timing of a terminal station, which is performed at a base station in a Time-Division Duplex communication system, is disclosed. The method includes (a) receiving ranging signals or other reference signals, transmitted from a terminal station; (b) determining whether transmission timing at the terminal station is appropriate or not, by referring to the ranging signals transmitted from the terminal station; and (c) transmitting a value for adjusting the transmission timing at the terminal station. The value of the transmission timing is a value of the integral multiples of the timing offset detection capability of the ranging signal, or a value calculated by referring to the received reference signals, which have assigned with a different interval from an interval of the ranging signals.
    Type: Application
    Filed: September 20, 2016
    Publication date: January 12, 2017
    Inventors: Masayuki TAKEKAWA, Keigo HASEGAWA
  • Publication number: 20160309381
    Abstract: The present invention provides a wireless communication terminal which can flexibly select a base station according to communication quality and a load status and improve communication quality which a user experiences in a wireless communication system which does not include a handover mechanism and is not notified of availability of radio resources from each base station.
    Type: Application
    Filed: June 30, 2016
    Publication date: October 20, 2016
    Inventor: Keigo HASEGAWA
  • Patent number: 9467867
    Abstract: To establish a wireless link with a terminal station without interfering with a primary user of a frequency, in a system and method in which a base station accesses a management apparatus for managing the frequency available for wireless communication via the wireless link with the terminal station.
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: October 11, 2016
    Assignee: HITACHI KOKUSAI ELECTRIC, INC.
    Inventors: Keigo Hasegawa, Masayuki Takekawa
  • Publication number: 20160277938
    Abstract: To establish a wireless link with a terminal station without interfering with a primary user of a frequency, in a system and method in which a base station accesses a management apparatus for managing the frequency available for wireless communication via the wireless link with the terminal station.
    Type: Application
    Filed: November 13, 2014
    Publication date: September 22, 2016
    Inventors: Keigo HASEGAWA, Masayuki TAKEKAWA
  • Patent number: 9438329
    Abstract: A wireless communication terminal includes: an array antenna; a MAC processing section, provided to detect a first order system, that interprets information on a quiet period that the base station has informed of the MAC processing section in advance and generates a quiet period signal; a synthesizing section that weights signals received by antennas of the array antenna by using weighting coefficients, and combines the signals to produce a synthetic signal; and an array antenna control section that optimizes the weighting coefficients so as to reduce an interference signal received from the array antenna, over a period of presence of the quiet period signal. The optimized weighting coefficients are applied while downstream signals from the base station are being received, but are not applied while the primary usage system is being detected.
    Type: Grant
    Filed: November 19, 2013
    Date of Patent: September 6, 2016
    Assignee: Hitachi Kokusai Electric Inc.
    Inventors: Keat Beng Toh, Masayuki Takekawa, Keigo Hasegawa
  • Publication number: 20160227584
    Abstract: Provided is a wireless communication system that is capable of preventing interference between secondary use systems that do not use a database. The wireless communication system uses a white space for opposing communication between a base station and a terminal station. At startup, the base station transmits a preamble over a cycle that is n-times a frame length (where n is an integer 2 or greater), changes a set frequency channel if ranging is not detected from a terminal station within a fixed time interval, and begins normal operation using the set frequency channel if ranging is detected. At startup, the terminal station detects a preamble within a received signal, changes a set frequency channel if a peak is detected at each frame length, and transmits a ranging signal if peaks are detected for cycles that are n-times the frame length and peaks are not detected for other cycles.
    Type: Application
    Filed: September 5, 2014
    Publication date: August 4, 2016
    Inventors: Kei YANAGISAWA, Masayuki TAKEKAWA, Keigo HASEGAWA
  • Publication number: 20160227418
    Abstract: Disclosed is a wireless communication system using white spaces and a base station that does not have its own backhaul, starts wireless communications without radiating radio waves of frequencies causing interference with primary users. A BS being in isolation starts a wireless communication with a CPE, connected to the internet, so as to access a database to acquire a list of frequencies available for transmission. The BS uses a predetermined frequency to perform the wireless communication with the CPE, and acquires, via this wireless communication, the list of frequencies available for transmission. Thereafter, the BS performs wireless communications with the CPE and with another CPE on the basis of the acquired list of frequencies available for transmission. The BS can hold, in advance, information of the predetermined frequency for which it has been estimated that the BS will cause no interference with the wireless communications of the primary users.
    Type: Application
    Filed: September 10, 2014
    Publication date: August 4, 2016
    Applicant: HITACHI KOKUSAI ELECTRIC INC.
    Inventors: Masayuki TAKEKAWA, Keigo HASEGAWA, Kei YANAGISAWA, Keat Beng TOH
  • Publication number: 20160135196
    Abstract: There is provided a wireless communication system that is capable of preventing interference with a primary use system caused by a CPE emitting radio waves at a frequency which is not a transmittable frequency before acquiring a list of transmittable frequencies based on its position information. In a wireless communication system that uses white space, a BS 10 and a CPE 22 store a specific frequency which is guaranteed to not interfere with a primary user. The BS 10 regularly switches between a first period when communication is performed at an operating frequency that uses white space and a second period when communication is performed at the specific frequency.
    Type: Application
    Filed: March 28, 2014
    Publication date: May 12, 2016
    Inventors: Masayuki TAKEKAWA, Keigo Hasegawa, Kei YANAGISAWA