Patents by Inventor Hijin Sato

Hijin Sato 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: 7373103
    Abstract: In a relay terminal A for relaying packet communication between a destination terminal C located outside a service area of a base station Z, and the base station Z, a contribution to relaying is measured and the measurement result is transmitted to a billing server SA configured to store an information communication charge of the relay terminal A, whereby it becomes feasible to give the relay terminal an incentive.
    Type: Grant
    Filed: October 2, 2002
    Date of Patent: May 13, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Yasushi Yamao
  • Patent number: 7305247
    Abstract: The present invention allows the cell shape of any base station in operation to be changed, thereby enabling services to be provided according to the needs. A mobile terminal attempts to synchronize with a perch channel to thereby check whether or not it can receive the signal, thereby determining whether it belongs to the cell of the base station. The mobile terminal uses the GPS to obtain location information to identify the location and notifies a cell control apparatus of results for cell determinations and location information. The cell control apparatus selects a base station for which the corresponding cell shape is to be changed, on the basis of the results for cell determinations and the location information. The cell control apparatus instructs the selected base station to change its cell shape. The base station changes its cell shape according to the instruction.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: December 4, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda
  • Patent number: 7292860
    Abstract: When a base station of a mobile communications system attempts to reduce its cell radius for power saving, frequency re-use enhancement and the like, a risk is that an ongoing communication between a mobile station served by the base station may be disconnected, which is avoided by: the base station transmitting information about a new cell radius to mobile stations in the current cell; the mobile stations responding to the base station with a positive or a negative reply determined from the information received from the base station; the base station suspending or revising the attempted cell radius reduction according to the responses from the mobile stations; and further by the mobile stations being capable of performing hand-over more efficiently than ever owing to abilities to detect final cell radii of adjacent base stations.
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: November 6, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hideki Tobe, Hijin Sato
  • Patent number: 7254132
    Abstract: In a wireless base station, when a newly provided control unit receives an IP packet from one mobile station (102), it refers to a destination address in control information added to the IP packet (104), and determines whether the IP packet is one to be broadcast or multicast (106). If the value of destination address is at a value indicative of broadcasting or the like defined by IP, the IP packet is copied according to the subnet, and is sent back to a wireless link layer processor with its contents intact (108). Further, the wireless link layer processor is commanded to broadcast the sent-back IP packet in a wireless area and so forth (110), whereby the IP packet can be broadcast into a cell and so forth.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: August 7, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Toshiaki Takao, Kobaruto Shimada, Narumi Umeda, Hijin Sato
  • Patent number: 7254409
    Abstract: The present invention is configured such that, in a multicast service providing system in which multicast information distribution service is made from an information distributing apparatus to radio terminals present within a service area via a radio section, the radio terminal has service continuation request signal transmitting a service continuation request signal for requesting continuation of the multicast information distribution service to the information distributing apparatus, the information distributing apparatus has service continuation management means managing as to whether or not request for the service continuation has been made by the radio terminal for the multicast information distribution service, and the information distributing apparatus transmits information indicating as to whether or not continuation request has been made for the multicast information distribution service managed by the service continuation management means.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: August 7, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Kobaruto Shimada, Toshiaki Takao, Narumi Umeda
  • Publication number: 20070162810
    Abstract: In a retransmission control method for a multicast information distribution service, when information which requires retransmission is generated, a wireless terminal transmits the retransmission request for the information to an information distribution apparatus when a timing determined for the wireless terminal is reached. The information distribution apparatus which receives the retransmission request transmits retransmission information which indicates the information requested by the retransmission request, with respect to each of the wireless terminals within the service area, and retransmits the information requested by the retransmission request at a predetermined timing.
    Type: Application
    Filed: March 5, 2007
    Publication date: July 12, 2007
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hijin SATO, Kobaruto Shimada, Toshiaki Takao, Narumi Umeda
  • Patent number: 7184784
    Abstract: The present invention is configured such that, in a multicast service providing system in which multicast information distribution service is made from an information distributing apparatus to radio terminals present within a service area via a radio section, the radio terminal has service continuation request signal transmitting a service continuation request signal for requesting continuation of the multicast information distribution service to the information distributing apparatus, the information distributing apparatus has service continuation management means managing as to whether or not request for the service continuation has been made by the radio terminal for the multicast information distribution service, and the information distributing apparatus transmits information indicating as to whether or not continuation request has been made for the multicast information distribution service managed by the service continuation management means.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: February 27, 2007
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Kobaruto Shimada, Toshiaki Takao, Narumi Umeda
  • Patent number: 7155234
    Abstract: A determination part obtains an available communication quality value from required communication quality values of terminals currently on connection, and a maximum permissible communication quality value determined according to a design of the radio communication system, and, when the available communication quality value is larger than a required communication quality value of a new terminal, the determination part accepts connection for the new terminal.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: December 26, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Daisuke Kitazawa, Hijin Sato, Narumi Umeda
  • Patent number: 7136662
    Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: November 14, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda, Toshiaki Takao, Kobaruto Shimada
  • Patent number: 7130636
    Abstract: At each wireless terminal, a receiving unit receives a signal transmitted from a wireless base station. A signal-to-noise ratio measurement unit measures an S/N of this received signal. In the wireless base station, data amount measurement unit measures the amount of data stored in each buffer therein. A maximum stay time measurement unit measures a maximum stay time of packets in each buffer. A classification by the maximum stay time unit classifies each wireless terminal based on the maximum stay time. A slot assignment priority order determination unit determines an assignment order of time slots to each wireless terminal based on the classification result in the classification unit, the receiving signal-to-noise ratio, the amount of data, and the maximum stay time.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: October 31, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Daisuke Kitazawa, Hijin Sato, Narumi Umeda
  • Patent number: 7110769
    Abstract: When a base station of a mobile communications system attempts to reduce its cell radius for power saving, frequency re-use enhancement and the like, a risk is that an ongoing communication between a mobile station served by the base station may be disconnected, which is avoided by: the base station transmitting information about a new cell radius to mobile stations in the current cell; the mobile stations responding to the base station with a positive or a negative reply determined from the information received from the base station; the base station suspending or revising the attempted cell radius reduction, according to the responses from the mobile stations; and further by the mobile stations being capable of performing hand-over more efficiently than ever owing to abilities to detect final cell radii of adjacent base stations.
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: September 19, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hideki Tobe, Hijin Sato
  • Publication number: 20060172731
    Abstract: When a base station of a mobile communications system attempts to reduce its cell radius for power saving, frequency re-use enhancement and the like, a risk is that an ongoing communication between a mobile station served by the base station may be disconnected, which is avoided by: the base station transmitting information about a new cell radius to mobile stations in the current cell; the mobile stations responding to the base station with a positive or a negative reply determined from the information received from the base station; the base station suspending or revising the attempted cell radius reduction according to the responses from the mobile stations; and further by the mobile stations being capable of performing hand-over more efficiently than ever owing to abilities to detect final cell radii of adjacent base stations.
    Type: Application
    Filed: April 3, 2006
    Publication date: August 3, 2006
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hideki Tobe, Hijin Sato
  • Publication number: 20060160549
    Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.
    Type: Application
    Filed: March 14, 2006
    Publication date: July 20, 2006
    Applicant: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda, Toshiaki Takao, Kobaruto Shimada
  • Patent number: 7006847
    Abstract: A base station for use in a multi-network connection communication system and its connecting method are provided, wherein the base station is connectable simultaneously to a carrier network and a private network. The base station comprises a section for making a decision as to whether a terminal is to be connected to a carrier network or a private network, and a section for connecting the terminal to the carrier network or the private network in accordance with the decision result.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: February 28, 2006
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda, Yasushi Yamao
  • Publication number: 20050222948
    Abstract: In a relay terminal A for relaying packet communication between a destination terminal C located outside a service area of a base station Z, and the base station Z, a contribution to relaying is measured and the measurement result is transmitted to a billing server SA configured to store an information communication charge of the relay terminal A, whereby it becomes feasible to give the relay terminal an incentive.
    Type: Application
    Filed: October 2, 2002
    Publication date: October 6, 2005
    Applicant: NTT DoCoMo Inc.
    Inventors: Hijin Sato, Yasushi Yamao
  • Patent number: 6895216
    Abstract: The method of invention provides a multicast service from an information delivery apparatus to wireless terminals through wireless routes. The method includes the step of transmitting, from the information delivery apparatus, a plurality of sets of multicast information, wherein these sets are identical to each other as to contents thereof but differ in transmission conditions. The method further includes the step of receiving, at any given one of the wireless terminals, one of the sets of multicast information being transmitted under one of the differing transmission conditions.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: May 17, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda, Yasushi Yamao
  • Patent number: 6882845
    Abstract: An autonomous zone forming method of autonomously forming a zone which is a service area of a base station in a wireless communication system having the base station is provided. In the method, it is detected that a zone is newly formed around the base station, and a zone which is the service area of the base station is autonomously changed according to a newly formed zone. When determining the zone, receive quality of a signal received from a surrounding base station is used. In addition, a congestion state of a surrounding base station of the base station is detected, and a zone which is the service area of the base station is enlarged to the direction of the surrounding base station according to the congestion state.
    Type: Grant
    Filed: February 2, 2001
    Date of Patent: April 19, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hijin Sato, Narumi Umeda, Yasushi Yamao
  • Patent number: 6871071
    Abstract: In handover control methods and systems which switch a radio base station serving as a communicating counterpart of a mobile station, the present invention provides a handover control method and a system thereof wherein a detection is made when a communication while a predetermined minimum bandwidth secured is not possible at any mobile station communicating with the radio base station and upon the detection the communicating counterpart of the mobile station that communicates with the radio base station mentioned above is switched from the radio base station to other radio base stations.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: March 22, 2005
    Assignee: NTT DoCoMo, Inc.
    Inventors: Toshiaki Takao, Hijin Sato, Narumi Umeda
  • Publication number: 20030157966
    Abstract: One preferred embodiment of the invention provides a wireless base station which provides a multicasting service to simultaneously transmit identical data to a plurality of wireless terminals. A wireless base station is connected to a plurality of wireless terminals and provides a multicasting service for a plurality of wireless terminals. The wireless base station determines autonomously whether it provides the multicasting service for the plurality of wireless terminals. Another preferred embodiment of the invention provides a method of selecting a wireless base station for a wireless terminal, the wireless base station providing a multicasting service for the wireless terminal. When the wireless terminal can receive the same multicasting information from a plurality of wireless base stations, the wireless terminal selects one of the plurality of wireless base stations so as to make the number of the wireless base stations that send the same multicasting information as small as possible.
    Type: Application
    Filed: January 29, 2002
    Publication date: August 21, 2003
    Inventors: Hijin Sato, Narumi Umeda, Toshiaki Takao, Kobaruto Shimada
  • Publication number: 20030050066
    Abstract: When a base station of a mobile communications system attempts to reduce its cell radius for power saving, frequency re-use enhancement and the like, a risk is that an ongoing communication between a mobile station served by the base station may be disconnected, which is avoided by: the base station transmitting information about a new cell radius to mobile stations in the current cell; the mobile stations responding to the base station with a positive or a negative reply determined from the information received from the base station; the base station suspending or revising the attempted cell radius reduction, according to the responses from the mobile stations; and further by the mobile stations being capable of performing hand-over more efficiently than ever owing to abilities to detect final cell radii of adjacent base stations.
    Type: Application
    Filed: September 10, 2002
    Publication date: March 13, 2003
    Applicant: NTT DoCoMo, Inc
    Inventors: Hideki Tobe, Hijin Sato