Patents by Inventor Koichi Ebata

Koichi Ebata 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: 8775461
    Abstract: A case search system for searching for a case that serves as a reference in a design or operation of a wireless network. The case search system includes a case database in which, for a case of design or operation of a wireless network, environment information that determines environmental characteristics of a wireless network in an area associated with the case is registered, and a case search unit that searches the case database for a case which serves as a reference using, as a search key, environment information that determines environmental characteristics of a wireless network in a target area which is a subject matter of the design or operation of the wireless network.
    Type: Grant
    Filed: April 29, 2009
    Date of Patent: July 8, 2014
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 8639217
    Abstract: A system is connected to an access point via a network, receives packet transmission information held by the access point, and extracts an address having a transfer destination which is radio interface from the packet transmission information. It is assumed that the terminal of the extracted address exists under the access point holing the packet transmission information. Thus, it is possible to realize connection relationship between a terminal and an access point at low cost and not depending on the vendor.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: January 28, 2014
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 8526980
    Abstract: An area to be estimated is sectioned to minute sections, the received signal qualities from a plurality of installed base stations (51, 52) are found, respectively in each of the minute sections, a difference between the received signal quality of each minute section and the received signal quality of a minute section adjacent to the above minute section is referred to as well as a change point at which a difference between a received signal quality used as a hand-over condition and the above received signal quality changes is detected so that an area in which a hand-over occurs can be accurately estimated. With this manner, there can be obtained a received signal quality estimation method capable of estimating an area in which a hand-over occurs very accurately in a mobile communication system.
    Type: Grant
    Filed: June 15, 2006
    Date of Patent: September 3, 2013
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 8374608
    Abstract: A reception quality estimating method estimates reception quality of a wireless communication area for estimating success or failure of handover processing occurring in a service area of a wireless communication system including a plurality of base stations. The method includes a first step and a second step. In the first step, the reception qualities of radio waves from the plurality of base stations are grasped at a given location within the service area. In the second step, the start point and end point of the handover processing are estimated by referring to time required for the handover processing, moving speed of a mobile terminal, which are previously input, and the reception qualities, and then success or failure of the handover processing is estimated by referring to the reception qualities of radio waves from the base stations at the start point and end point of the handover processing.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: February 12, 2013
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 8174998
    Abstract: In a network connecting apparatus, relations of targets and attributions of the targets are registered in a attribution table and relations of the attributions and available connection settings are registered in a connection setting table. An attribution determining section is configured to specify a target when detecting a request of a wireless communication associated with the target, and refer to the attribution table to determine the attribution of the target. A connection setting section is configured to change a connection setting based on the target attribution by referring to the connection setting table. A connecting section is configured to execute a connecting process for the wireless communication based on the connection setting.
    Type: Grant
    Filed: April 20, 2009
    Date of Patent: May 8, 2012
    Assignee: NEC Corporation
    Inventors: Koichi Ebata, Kazuhiro Okanoue, Akira Miyashita
  • Patent number: 8135421
    Abstract: The above base-station cell design method is for sequentially adding base stations, and a technique of which throughput is few is employed for a radio-wave propagation characteristic evaluation to be made in this addition, and a technique of which the throughput is much, but which is of high-precision, more specifically, a technique such as the ray tracing is applied for the radio-wave propagation characteristic evaluation to be made after addition. The result of the high-precision radio-wave propagation characteristic evaluation to be made after this addition is put to practical use for estimating an interference quantity in selecting the arrangement location of the base station to be added newly. This allows the quantity of the radio wave analytic processing, which accounts for a large majority of the base-station cell design processing, to be reduced, thus enabling a fast base-station cell design.
    Type: Grant
    Filed: February 21, 2006
    Date of Patent: March 13, 2012
    Assignee: NEC Corporation
    Inventors: Hiroshi Furukawa, Koichi Ebata
  • Patent number: 8027275
    Abstract: A control packet is broadcast over a route, containing first and second metric values of different transmission characteristics of the route. At a local node, control packets from multiple nodes are received and examined for their source. If the packets are received from upstream nodes, the metrics of the received packets are updated, the second metric is weighted and summed with the first metric to produce a number of combined metrics and a minimum value of the combined metrics is detected. One of the routes having the detected value is selected as a route to an upstream node. If the control packets are received from downstream nodes, the second metric is weighted and summed with the first metric to produce a number of combined metrics and a smaller values of combined metrics are detected corresponding in number to usable antennas and routes of the detected values are selected.
    Type: Grant
    Filed: March 20, 2003
    Date of Patent: September 27, 2011
    Assignee: NEC Corporation
    Inventors: Koichi Ebata, Hiroshi Furukawa
  • Publication number: 20100265894
    Abstract: In a network connecting apparatus, relations of targets and attributions of the targets are registered in a attribution table and relations of the attributions and available connection settings are registered in a connection setting table. An attribution determining section is configured to specify a target when detecting a request of a wireless communication associated with the target, and refer to the attribution table to determine the attribution of the target. A connection setting section is configured to change a connection setting based on the target attribution by referring to the connection setting table. A connecting section is configured to execute a connecting process for the wireless communication based on the connection setting.
    Type: Application
    Filed: April 20, 2009
    Publication date: October 21, 2010
    Inventors: KOICHI EBATA, Kazuhiro Okanoue, Akira Miyashita
  • Patent number: 7756523
    Abstract: A managing server 1 and a propagation characteristic computing server 3 grasp a load situation for each cell that is a coverage range of each of a plurality of APs 4a to 4d, calculate an evaluation value defined for evaluating the load situation, and take a control of the load situation of each cell so that this evaluation value is minimized. The control of load situation is a control for altering a shape (including size) of each cell, and further, specifically, a control for making a cell alteration so that the above-mentioned evaluation value is minimized, by performing processes such as regulation of the transmission power of the AP, alteration of the installation position of the AP and addition of the AP. This allows the load of each cell (AP) to be regulated most suitably.
    Type: Grant
    Filed: October 5, 2004
    Date of Patent: July 13, 2010
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Publication number: 20100057422
    Abstract: The object is to reduce the amount of processing in network simulation executed at the time of evaluating communication quality of a wireless LAN and reduce computation time of simulation based on a set radio wave propagation situation. At a step of executing network simulation in a wireless LAN communication quality evaluation method using network simulation, a situation of arrival of a radio wave transmitted by a terminal at other access point or other terminal is considered to be the same as a situation of arrival of a radio wave transmitted by an access point to which the terminal belongs at other access point or an access point to which other terminal belongs.
    Type: Application
    Filed: October 5, 2007
    Publication date: March 4, 2010
    Applicant: NEC Corporation
    Inventors: Koichi Ebata, Wataru Domon
  • Publication number: 20090282024
    Abstract: A case search system for searching for a case that serves as a reference in a design or operation of a wireless network. The case search system includes a case database in which, for a case of design or operation of a wireless network, environment information that determines environmental characteristics of a wireless network in an area associated with the case is registered, and a case search unit that searches the case database for a case which serves as a reference using, as a search key, environment information that determines environmental characteristics of a wireless network in a target area which is a subject matter of the design or operation of the wireless network.
    Type: Application
    Filed: April 29, 2009
    Publication date: November 12, 2009
    Applicant: NEC CORPORATION
    Inventor: Koichi EBATA
  • Publication number: 20090262686
    Abstract: Session management means holds session information concerning sessions for fixed terminals and sessions for mobile terminals including type information indicating a terminal type and status information indicating the status of communication. Session clear-out means disconnects a session the type information for which indicates a mobile terminal and in which communication has not been performed for a time period longer than or equal to a first monitoring time period, on the basis of the session information held in the session management means.
    Type: Application
    Filed: June 16, 2009
    Publication date: October 22, 2009
    Inventors: Koichi Ebata, Kazuhiro Okanoue, Akira Miyashita
  • Publication number: 20090239532
    Abstract: An area to be estimated is sectioned to minute sections, the received signal qualities from a plurality of installed base stations (51, 52) are found, respectively in each of the minute sections, a difference between the received signal quality of each minute section and the received signal quality of a minute section adjacent to the above minute section is referred to as well as a change point at which a difference between a received signal quality used as a hand-over condition and the above received signal quality changes is detected so that an area in which a hand-over occurs can be accurately estimated. With this manner, there can be obtained a received signal quality estimation method capable of estimating an area in which a hand-over occurs very accurately in a mobile communication system.
    Type: Application
    Filed: June 15, 2006
    Publication date: September 24, 2009
    Applicant: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 7590081
    Abstract: A radio network can select a route of minimum path loss among entire relay routes and can set the relay route so as to satisfactorily resist interference. The radio network has a core node connected to a wired network, relay nodes each relaying at least one of a down-link data packet transmitted from the core node and an up-link data packet directed toward the core node, and a terminal station capable of transmission and reception of data packets with both the core node and the relay node. The relay node has total path loss optimized to be minimum between relay nodes included in a relay route of the data packet or between the relay node and the core node or both.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: September 15, 2009
    Assignee: NEC Corporation
    Inventors: Hiroshi Furukawa, Morihisa Momona, Koichi Ebata
  • Patent number: 7577436
    Abstract: An operation management system in a radio communication system, including a plurality of wireless base stations, includes: a cell determining means for determining a boundary of a cell by: collecting power transmitted, and antenna gain, from each wireless base station, computing a propagation loss from each of the wireless base stations at an arbitrary observation point, using a statistical technique employing an estimation model in which a radio wave damps depending upon distance or by use of a ray-tracing method, computing power received from each wireless base station at the observation point, deciding that the wireless base station that achieves maximum received power at the observation point is a connection base station at the observation point, and determining the space between points in which connection base stations differ as cell boundaries.
    Type: Grant
    Filed: September 1, 2004
    Date of Patent: August 18, 2009
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 7554936
    Abstract: A radio network can select a route of minimum path loss among entire relay routes and can set the relay route so as to satisfactorily resist interference. The radio network has a core node connected to a wired network, relay nodes each relaying at least one of a down-link data packet transmitted from the core node and an up-link data packet directed toward the core node, and a terminal station capable of transmission and reception of data packets with both the core node and the relay node. The relay node has total path loss optimized to be minimum between relay nodes included in a relay route of the data packet or between the relay node and the core node or both.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: June 30, 2009
    Assignee: NEC Corporation
    Inventors: Hiroshi Furukawa, Morihisa Momona, Koichi Ebata
  • Patent number: 7552034
    Abstract: When locating base stations which are wirelessly coupled with each other and establish one or more inter-cell wireless relay routes in a mobile communications system, the heights of directional antennas to be installed at the base stations are determined so as to be different, which base stations are adjacent with each other in a given inter-cell wireless relay route.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: June 23, 2009
    Assignee: NEC Corporation
    Inventors: Koichi Ebata, Hiroshi Furukawa
  • Patent number: 7532629
    Abstract: In a source node of a multi-hop network is provided with a route table in which a number of routes from the node to all destinations are mapped to hop count numbers. In response to a request for transmission of data, the node determines a hop count number from the route table corresponding to a route indicated in the request and segments the data into a number of data segments according to the hop count number. The data segments are converted into packets and transmitted. In a transit node, the packets are placed into one of a set of queuing buffers that corresponds to the hop count number of the packets. The stored packets are scheduled for transmission according to their hop count number.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: May 12, 2009
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 7515911
    Abstract: A task is to automatically carry out directional control of an antenna in parallel with routing in a radio network. In the event that a radio transmission apparatus 100, which is a node configuring the radio network, received a routing packet 200 from the node over the radio network, it acquires and records a received direction of the routing packet 200, an identifier of a transmission source node, metric information indicating a route cost, and an identifier of a route destination node, and in the event that the route destination node is not its own node, the radio transmission apparatus 100 takes control so as to match a direction of an antenna system 101 to the received direction of the node having minimum metric information out of the recorded metric information.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: April 7, 2009
    Assignee: NEC Corporation
    Inventor: Koichi Ebata
  • Patent number: 7461185
    Abstract: A data transfer system allowing high-quality transfer of streaming data through a network having a relatively large delay variation in data delivery is disclosed. When transferring streaming data in packets from a server computer to a client computer through a repeater provided in the network, the repeater buffers a streaming packet for a set time period before forwarding it to the client computer. The set time period is determined so that a receiving time interval of packets at the client computer is substantially equal to a sending time interval of packets at the server computer.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: December 2, 2008
    Assignee: NEC Corporation
    Inventors: Koichi Ebata, Kenji Takeda