Patents by Inventor Takehiro Nakamura

Takehiro Nakamura 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: 7725121
    Abstract: A mobile communication system includes wireless base stations, a mobile station communicating with the wireless base stations, and a radio network controller controlling the wireless base stations. The mobile communication system includes a power controller which controls a power of control bits in downlink based on the number of wireless base stations simultaneously communicating with the mobile station.
    Type: Grant
    Filed: January 12, 2006
    Date of Patent: May 25, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Takehiro Nakamura
  • Patent number: 7720508
    Abstract: A radio controller includes: a schedule information receiver for receiving schedule information related to a schedule of data transmission; a selection execution determiner for determining, based on the schedule information, whether or not to select a cell used by a mobile station after the data reception; and a selection execution commander for commanding the mobile station to select the cell used after the data reception in accordance with a determination result by the selection execution determiner.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: May 18, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Minami Ishii, Takehiro Nakamura
  • Publication number: 20100120448
    Abstract: A tracking area setting apparatus is disclosed that includes a service request measurement unit measuring a frequency of occurrence of a service request transmitted by a user equipment terminal to a cell where the user equipment terminal is located based on a paging channel transmitted in all cells belonging to a tracking area where the user equipment terminal is located, the user equipment terminal being a target user equipment terminal to receive a call, the tracking area including one or more cells and a tracking area determination unit determining whether a number of the frequency of occurrence of the service request in a predetermined cell is equal to or greater than a predetermined threshold value based on the frequency of occurrence of the service request and, when determining yes, separate the predetermined cell from the tracking area to which the predetermined cell belongs.
    Type: Application
    Filed: January 30, 2008
    Publication date: May 13, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Takehiro Nakamura, Yasuhiro Kato, Wuri Andarmawanti Hapsari
  • Publication number: 20100118805
    Abstract: A user apparatus which wirelessly communicates with a base station apparatus within a mobile communications system is disclosed. The user apparatus includes a receive unit which receives control information in downlink; and a transmit unit which transmits a first channel in uplink, wherein the transmit unit, based on the control information, makes a value of a maximum transmit power of the first channel smaller than that of a nominal power specified for the mobile communications system.
    Type: Application
    Filed: March 21, 2008
    Publication date: May 13, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Takehiro Nakamura
  • Publication number: 20100113022
    Abstract: An upper node and a handover source radio base station store setup information on an access bearer having been set up between the upper node and the handover source radio base station. A mobile communication method according to the present invention includes the steps of: (A) informing, from the handover source radio base station to a handover target radio base station, the access bearer setup information; (B) storing, at the handover target radio base station, the access bearer setup information informed of by the handover target radio base station; and (C) setting up, at the upper node, an access bearer between the upper node and the handover target radio base station by using the stored access bearer setup information without performing reallocation processing of new access bearer setup information, the access bearer being set up in response to a path switching request from the handover target radio base station.
    Type: Application
    Filed: March 7, 2008
    Publication date: May 6, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Masayuki Motegi, Wuri Andarmawanti Hapsari, Yoshitsugu Shimazu, Yasuhiro Kato, Takehiro Nakamura
  • Publication number: 20100105377
    Abstract: A disclosed base station apparatus to be used in a mobile communication system includes a report signal receiving unit receiving a report signal from one or more user equipment terminals, a radio parameter adjustment unit adjusting radio parameters based on an analysis result of each report signal, a designation unit designating a report condition to be used for each user equipment terminal to determine whether to transmit the report signal and content to be reported in the report signal, and a report unit reporting the report condition and the content to be reported to the one or more user equipment terminals. Further, in the base station apparatus, the report condition is satisfied when a transmission source of a downlink reference signal is a specific cell, and the content to be reported includes a received quality value of the downlink reference signal.
    Type: Application
    Filed: December 21, 2007
    Publication date: April 29, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Takehiro Nakamura, Yasuhiro Kato, Yoshitsugu Shimazu, Masayuki Motegi
  • Patent number: 7702339
    Abstract: The object of the present invention is to provide a base station 10, a mobile station 11 and a radio network controller 50 which can reduce the load on the radio network controller 50 during multicast communication. The base station 10 supporting multicast communication comprises a response signal relay 10b configured to transfer response signals transmitted from a plurality of mobile stations 11, 12, 21, 41, 42 to a radio network controller 50. The response signals respond to a control signal for a multicast group. The response signal relay 10b transfers only a predetermined number of response signals to the radio network controller 50. Any following response signals are retained.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: April 20, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takehiro Nakamura, Minami Ishii, Shinji Ueda
  • Patent number: 7701906
    Abstract: There is provided a handover control method that does not produce quality deterioration or other similar problems during handover in a mobile communication system in which a first channel shared by a plurality of mobile stations and second channels exclusively used by respective mobile are used in combination.
    Type: Grant
    Filed: October 29, 2002
    Date of Patent: April 20, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yoshihiro Ishikawa, Takahiro Hayashi, Mikio Iwamura, Takehiro Nakamura
  • Patent number: 7702344
    Abstract: A radio communication system includes a radio network controller, base stations and mobile stations. The mobile station includes a response signal transmitter which is configured to transmit a response signal including a group ID identifying a multicast group A to a base station. The response signal responds to a control signal for the multicast group A which the mobile station is joining in. The base station includes a response signal transmitter configured to transmit at least one response signal to the radio network controller. The response signal is selected from at least one response signal transmitted from the mobile station joining in the same multicast group A.
    Type: Grant
    Filed: September 17, 2003
    Date of Patent: April 20, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takehiro Nakamura, Minami Ishii, Shinji Ueda
  • Patent number: 7697483
    Abstract: A transmission method according to the present invention includes: concatenating CRC masking data and receiver identification information for identifying the receiver; generating CRC check bits by performing a CRC encoding processing against non-CRC masking data; masking the CRC check bits by the concatenated receiver identification information and CRC masking data; concatenating the masking result and the non-CRC masking data; generating a transmission signal by performing an FEC encoding processing against the concatenated masking result and the non-CRC masking data, which are added; and transmitting the transmission signal to the receiver.
    Type: Grant
    Filed: April 4, 2006
    Date of Patent: April 13, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Publication number: 20100087200
    Abstract: The base station apparatus calculates the number of the mobile stations associated with a consumption amount of radio resources, and carries out call admission control in accordance with the number of the mobile station. The base station apparatus includes a calculation section that calculates the number of the mobile stations having data to be transmitted in a transmission buffer, and a call admission section that carries out new call admission in accordance with the number of the mobile stations.
    Type: Application
    Filed: December 27, 2007
    Publication date: April 8, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Takehiro Nakamura
  • Publication number: 20100086070
    Abstract: A user apparatus that communicates with a base station apparatus in a mobile communication system includes: a plurality of antennas; a selection unit configured to select an antenna according to a frequency; and a reception unit configured to receive a signal using the antenna selected by the selection unit. The selection unit selects all of the plurality of antennas when the frequency is greater than a predetermined threshold (1 GHz, for example), and the selection unit selects one of the plurality of antennas when the frequency is not greater than a predetermined threshold.
    Type: Application
    Filed: March 12, 2008
    Publication date: April 8, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Takehiro Nakamura
  • Patent number: 7693170
    Abstract: A transmission rate control method, includes: transmitting, at a radio base station, a relative rate grant channel which includes a command for controlling a transmission rate in uplink to a mobile station; and determining, at the mobile station, that the relative rate grant channel which includes a HOLD command for instructing to maintain the transmission rate is received at the mobile station, when data to be transmitted becomes empty in a transmission buffer and a receive signal in the relative rate grant channel is detected as “0” or “+1”, and maintaining the transmission rate.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: April 6, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7693537
    Abstract: A transmission rate control method for controlling a transmission rate of a channel to which the transmission rate control method is applied, include: notifying, at a radio network controller, at a timing of a call setup or the like, a primary allowable transmission rate of the channel to which the transmission rate control method is applied; starting, at a mobile station, after the call setup, transmission at a transmission rate below the primary allowable transmission rate, when data to be transmitted is generated; and controlling, at the mobile station, the transmission rate of the channel to which the transmission rate control method is applied, based on an Absolute Grant Channel transmitted from a radio base station.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: April 6, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7693539
    Abstract: A mobile communication system comprises: a determination unit configured to determine as to layers of data to be transmitted by base stations to mobile stations for respective radio areas, based on area resource information concerning radio resources for the respective radio areas covered by the base stations; and a radio transmitter configured to transmit the data to the mobile stations according to a determination of the determination unit.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: April 6, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Mayu Yamada, Takehiro Nakamura, Minami Ishii, Masafumi Usuda, Sung Uk Moon, Akihito Hanaki
  • Publication number: 20100080135
    Abstract: A base station for communicating with a mobile station which transmits an uplink signal according to a frequency division multiplexing scheme includes a first measurement unit configured to measure reception power on a frequency band for the random access channel in uplink or a second measurement unit configured to measure the number of receptions of preambles on the random access channel. The base station may either control the frequency band for the random access channel or restrict transmission on the random access channel based on at least one of the reception power on the frequency band for the random access channel and the number of receptions of preambles on the random access channel.
    Type: Application
    Filed: January 15, 2008
    Publication date: April 1, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Satoshi Nagata, Takehiro Nakamura, Mikio Iwamura
  • Publication number: 20100069076
    Abstract: A radio base station for establishing a signaling control channel and a shared data channel for a mobile station and communicating with the mobile station includes a broadcast information generating unit configured to generate broadcast information including one or more information blocks; a scheduling information generating unit configured to generate scheduling information for the one or more information blocks; and a broadcast information transmitting unit configured to transmit the scheduling information as part of the broadcast information.
    Type: Application
    Filed: October 2, 2007
    Publication date: March 18, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Minami Ishii, Sadayuki Abeta, Takehiro Nakamura
  • Patent number: 7680207
    Abstract: The object of the present invention is provide a mobile communication system which can improve a communication quality of the mobile communication system as a whole by changing a transmission method for transmitting common information. Each of the mobile stations 200a to 200l comprises a communication quality measurer 230 configured to measure a communication quality of a signal transmitted from the radio station 100a.
    Type: Grant
    Filed: October 6, 2003
    Date of Patent: March 16, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takehiro Nakamura, Minami Ishii, Masafumi Usuda, Mayu Yamada, Akihito Hanaki
  • Patent number: 7680072
    Abstract: A radio communications system of this invention is configured to control transmission power of a shared control channel for transmitting control signals to a plurality of mobile stations. The radio communications system has a transmission power controller configured to control the transmission power of the shared control channel, in accordance with transmission power of a dedicated channel accompanying the shared control channel, and communication quality of the shared control channel.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: March 16, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Masafumi Usuda, Takehiro Nakamura
  • Publication number: 20100062774
    Abstract: A handover method according to the present invention includes the steps of: forwarding, at a handover-source radio base station (eNB), user data (A) for a mobile station (UE) to a handover-target radio base station (eNB) when it is determined that a handover processing is to be performed, the user data (A) being stored in the handover-source radio base station (eNB); activating, at the handover-target radio base station, a predetermined timer when transmitting a path switch request to a path control apparatus, and storing second user data for the mobile station received from the path control apparatus until the predetermined timer expires; and forwarding, at the handover-target radio base station, the stored second user data to the mobile station after the predetermined timer expires.
    Type: Application
    Filed: March 7, 2008
    Publication date: March 11, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Masayuki Motegi, Yasuhiro Kato, Yoshitsugu Shimazu, Wuri Andarmawanti Hapsari, Takehiro Nakamura