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).

  • Publication number: 20100309840
    Abstract: A disclosed radio communication apparatus includes a unit receiving a broadcast channel including a system frame number (SFN), a control channel including a process number (Proc) and a new data identification, and a user data channel including a sequence number; a unit detecting whether a received first packet includes an error and reporting the detection result indicating ACK or NACK to a transmitter side; a unit detecting whether the control channel has not been correctly received in the past based on the process number and the new packet identification information of a second packet transmitted after the first packet; and a unit reporting an indicator including the SFN at which the second packet is transmitted to the transmitter side, so that a packet is re-transmitted, the packet being transmitted to the radio communication apparatus by a preceding SFN that precedes an SFN at which the second packet is transmitted.
    Type: Application
    Filed: June 15, 2007
    Publication date: December 9, 2010
    Applicant: NTT DoCoMo, INC.
    Inventors: Anil Umesh, Takehiro Nakamura
  • Publication number: 20100297998
    Abstract: A radio base station (T-eNB) according to the present invention is configured to set up a data forwarding tunnel for forwarding user plane data to the radio base station (T-eNB) only for an access bearer for which the user plane data to be forwarded exists, when receiving a notification from a handover-source radio base station (S-eNB) as to whether or not the user plane data to be forwarded exists for each access bearer, the notification being made by using a handover request message for the mobile station (UE), and the access bearer being set up between the radio base station (T-eNB) and a upper level node (SGW); and
    Type: Application
    Filed: October 30, 2008
    Publication date: November 25, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Wuri Andarmawanti Hapsari, Masayuki Motegi, Yasuhiro Kato, Yoshitsugu Shimazu, Takehiro Nakamura
  • Patent number: 7839821
    Abstract: A packet transmission control device and a packet transmission control method for reducing degradation of system throughput due to a wireless mobile station in an abnormal state, in controlling transmission of packets to each of a plurality of wireless terminals. A channel is assigned based on an evaluated value from an evaluation function containing an average transmission rate value for the wireless terminal in its denominator, and if the evaluated value falls in an abnormal value, the average transmission rate value is initialized to reduce the frequency of assigning packets to the wireless terminal if one of multiple wireless terminals transitions to an abnormal state. By initializing the average transmission rate value, a phenomenon that an unnecessarily large number of shared channels are assigned to a wireless mobile station in an abnormal state may be avoided to prevent degradation of overall system throughput.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: November 23, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Hiroyuki Ishii, Akihito Hanaki, Takehiro Nakamura
  • Patent number: 7835329
    Abstract: It is an object of this invention to select an information receiving method at a mobile station (MS) so as to avoid an increase in the transmission power of a base transceiver station (BTS) or redundancy or loss of received information at the mobile station (MS) in broadcast communication or multicast communication. A mobile station according to this invention includes a receiving method selection information acquiring unit (11, 14, 15, 16) for acquiring receiving method selection information for receiving the same information transmitted via a plurality of cells, and a determining unit (12) for determining whether to perform soft combining or selective combining on the same information based on the receiving method selection information.
    Type: Grant
    Filed: August 20, 2004
    Date of Patent: November 16, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Minami Ishii, Takehiro Nakamura
  • Publication number: 20100284475
    Abstract: The present invention provides a transmission rate control method for controlling the transmission rate of uplink user data, including the step of; a radio network controller notifies to a radio base station and a mobile station an effective period of an absolute transmission rate control channel, when a call is established or when a serving cell is changed; a radio base station determines whether or not to transmit the absolute transmission rate control channel to each of mobile stations which is performing a communication with the radio base station; and each of the mobile stations determines the transmission rate of the uplink user data, based on a maximum allowable transmission rate mapped to the absolute transmission rate control channel notified by the radio base station.
    Type: Application
    Filed: July 22, 2010
    Publication date: November 11, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Masafumi USUDA, Anil UMESH, Takehiro NAKAMURA
  • Patent number: 7826861
    Abstract: A base station including a transmitting and receiving amplifier for amplifying CDMA signals exchanged with a mobile station; a radio stage connected to the transmitting and receiving amplifier for carrying out D/A conversion of a transmitted signal that undergoes baseband spreading, followed by quadrature modulation, and for carrying out quasi-coherent detection of a received signal, followed by A/D conversion; a baseband signal processor connected with the radio stage for carrying out baseband signal processing of the transmitted signal and the received signal; a transmission interface connected with the baseband signal processor for implementing interface with external channels; and a base station controller for carrying out control such as management of radio channels and establishment and release of the radio channels. The base station communicates with the external channels by mapping logical channels into physical channels. The CDMA signals are spread using a short code and a long code.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: November 2, 2010
    Assignee: NTT Docomo, Inc.
    Inventors: Takehiro Nakamura, Junichiro Hagiwara, Etsuhiro Nakano, Koji Ohno, Seizo Onoe, Akihiro Higashi, Motoshi Tamura, Masatomo Nakano, Hiroshi Kawakami, Hiroki Morikawa
  • Publication number: 20100273448
    Abstract: In a mobile communication system according to the present invention, the mobile communication system is configured to manage a specific mobile station which is allowed to communicate through a CSG cell under the control of a home base station (Home-eNB); and a general mobile station (UE) other than the specific mobile station is configured to be capable of using the CSG cell as a camped cell, only when broadcast information indicating an allowance of a camping in the specific cell is received.
    Type: Application
    Filed: October 28, 2008
    Publication date: October 28, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Masafumi Masuda, Takaaki Sato, Takehiro Nakamura
  • Publication number: 20100267385
    Abstract: A cell selection method includes steps of: (A) determining, at a mobile station (UE), whether or not a first CSG cell satisfies a predetermined condition, when using a first macro cell as a camped cell; and (B) changing, at the mobile station (UE), the camped cell from the first macro cell to a first CSG cell, when determined that the first CSG cell satisfies the predetermined condition.
    Type: Application
    Filed: November 14, 2008
    Publication date: October 21, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Mikio Iwamura, Takehiro Nakamura
  • Patent number: 7817598
    Abstract: A transmission rate control method for controlling a transmission rate of uplink user data, includes: notifying, at a radio network controller, to a radio base station and a mobile station, an effective period to an Absolute Grant Channel which includes an absolute value for the transmission rate of the uplink user data, transmitting, at the radio network controller, the Absolute Grant Channel per Radio Network Temporary Identity based on the notified effective period; and determining, at the mobile station, the transmission rate of the uplink user data based on the notified effective period, when receiving the Absolute Grant Channel per Radio Network Temporary Identity from the radio base station.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: October 19, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7817597
    Abstract: A transmission rate control method for controlling transmission rate of layer-2 control information, including: notifying, at a radio network controller, a correspondence of a transmission data block size of the layer-2 control information to a transmission power ratio between an enhanced dedicated physical data channel and a dedicated physical control channel on the layer-2 control information, to a mobile station; determining, at the mobile station, a transmission power ratio of the layer-2 control information to be transmitted based on the correspondence; and transmitting, at the mobile station, the layer-2 control information using the determined transmission power ratio.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: October 19, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7813754
    Abstract: The present invention relates to a transmission rate control method of controlling a transmission rate of uplink user data to be transmitted from a mobile station to a radio base station. The method includes: starting to transmit at the mobile station, the uplink user data at an initial transmission rate which is informed from a network or an initial transmission rate which has been already informed from the network; and increasing at the mobile station the transmission rate of the uplink user data, up to a predetermined transmission rate, on a basis of a increase rule of the transmission rate which is beforehand determined.
    Type: Grant
    Filed: June 17, 2005
    Date of Patent: October 12, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Patent number: 7813705
    Abstract: A transmission rate control method for controlling transmission rate of uplink user data, including: notifying, at a radio network controller, a first correspondence of a transmission data block size of the uplink user data to a transmission wave amplitude ratio between an enhanced dedicated physical data channel and a dedicated physical control channel for the uplink user data, to a mobile station; generating, at the mobile station, a second correspondence of a transmission data block size of the uplink user data to a transmission power ratio between an enhanced dedicated physical data channel and a dedicated physical control channel for the uplink user data based on the notified first correspondence; notifying, at a radio base station, the transmission power ratio to the mobile station; and determining, at the mobile station, a transmission data block size of the uplink user data based on the notified transmission power ratio and the second correspondence.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: October 12, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Publication number: 20100234029
    Abstract: A mobile communication method according to the present invention includes: transmitting, from a mobile station (100) to an access node (200) in a first radio access technology, a connection request signal including a desired call type for communication and a radio access capability of the mobile station (100); determining, at the access node (200) in the first radio access technology, whether or not to perform handover to a second radio access technology on the basis of the desired call type for communication and the radio access capability of the mobile station included in the connection request signal; and transmitting, from the mobile station (100) to an access node in the second radio access technology, a connection request signal, when it is determined that the handover to the second radio access technology is to be performed.
    Type: Application
    Filed: September 5, 2008
    Publication date: September 16, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Minami Ishii, Takehiro Nakamura
  • Publication number: 20100220652
    Abstract: A base station apparatus to be used for a mobile communication system capable of providing communications using plural frequency carriers is disclosed. The base station apparatus includes a frequency carrier selection unit selecting one of a first frequency carrier and a second frequency carrier as a frequency carrier to be used for the communications based on at least one of a service type of the communications and a congestion degree of the communications, the first frequency carrier being used for communications based on allocation in which radio resources are dynamically allocated, the second frequency carrier being used for communications based on allocation in which the radio resources are allocated at every predetermined period.
    Type: Application
    Filed: June 16, 2008
    Publication date: September 2, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Hiroyuki Ishii, Takehiro Nakamura
  • Patent number: 7783320
    Abstract: A radio base station notifies a maximum allowable transmission rate of uplink user data to a mobile station by using a common transmission rate control channel. The mobile station increases the transmission rate of uplink user data up to the maximum allowable transmission rate by a predetermined step. When a predetermined condition is satisfied, the mobile station requests the radio base station to transmit a dedicated transmission rate control channel. The mobile station determines the transmission rate of uplink user data based on the dedicated transmission rate control channel transmitted from the radio base station.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: August 24, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Masafumi Usuda, Anil Umesh, Takehiro Nakamura
  • Publication number: 20100208628
    Abstract: A mobile communication system for performing two-way communication between a mobile station and a wireless access network apparatus. The mobile station comprises a connection setup signal reception timing calculating part that calculates the reception timing of a connection setup signal when a connection request signal is transmitted; and a connection setup signal determining part that determines, in accordance with the reception timing, whether the connection setup signal is received, and then performs, based on that determination, a reception process.
    Type: Application
    Filed: July 25, 2006
    Publication date: August 19, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Minami Ishii, Anil Umesh, Sadayuki Abeta, Takehiro Nakamura
  • Publication number: 20100188985
    Abstract: A mobile station includes a radio channel condition evaluation unit evaluating a radio channel condition; a radio channel condition averaging unit averaging the evaluated radio channel condition over a predefined time period; a radio channel condition threshold storage unit storing a threshold of the radio channel condition and a message type, the threshold and the message type being specified by a radio access network apparatus; a radio channel condition comparison unit comparing the averaged radio channel condition with the threshold; and a radio channel condition reporting unit transmitting an identifier and the radio channel condition for a cell to the radio access network apparatus, the averaged radio channel condition of the cell being greater than or equal to the threshold.
    Type: Application
    Filed: February 13, 2007
    Publication date: July 29, 2010
    Applicant: NTT DoCoMo, Inc.
    Inventors: Minami Ishii, Sadayuki Abeta, Takehiro Nakamura
  • Patent number: 7764964
    Abstract: A mobile communication system for transmitting a plurality of same information to a plurality of cells. The mobile communication system includes a transmission timing determining unit for determining a transmission timing of the same information to each of the cells randomly or in such a manner that transmission timings differ between the cells, and a transmitting unit for transmitting the same information to the cells at the determined transmission timings.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: July 27, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takehiro Nakamura, Minami Ishii, Anil Umesh
  • Publication number: 20100165950
    Abstract: In a disclosed method, a mobile station determines whether handover is intra-base-station based on a received signal; the mobile station sends a handover request indicating the determination result to a base station; the base station determines whether the handover is intra-base-station or inter-base-station based on the handover request; and the base station performs an intra-base-station handover process based on a CQI reception level threshold for intra-base-station handover if the handover is intra-base-station.
    Type: Application
    Filed: February 13, 2007
    Publication date: July 1, 2010
    Applicant: NTT DOCOMO, INC.
    Inventors: Sadayuki Abeta, Minami Ishii, Takehiro Nakamura
  • Patent number: 7738414
    Abstract: The present invention can improve a reception quality of mobile stations and utilize radio resources effectively, by resolving the problem caused when the conventional multicast communications system. The present invention relates to a radio communications system for transmitting same data to a plurality of cells via at least one base station and performing a soft combining or a selective combining on the same data received by a mobile station. The radio communications system includes a controlling unit configured to set up a cycle at which synchronization processing on transmission timing of the same data among the plurality of cells is performed, or an accuracy by which the synchronization processing is performed, for each control apparatus which performs the synchronization processing.
    Type: Grant
    Filed: December 24, 2004
    Date of Patent: June 15, 2010
    Assignee: NTT DoCoMo, Inc.
    Inventors: Sung Uk Moon, Takehiro Nakamura, Minami Ishii, Anil Umesh