Patents by Inventor Hidetoshi Yokota

Hidetoshi Yokota 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: 7436805
    Abstract: The present invention provide a method for call establishment over a packet exchange network which is capable of saving the time required for a call establishment of the PPP by reducing redundant steps for authentication in a SIP call, and to reduce the incoming data amount. The present invention comprising the following steps. Step (a): The TE requests the PDSN for CHAP authentication. This message is received by the AT on behalf of the PDSN. Step (b): The AT requests the TE for the CHAP authentication on behalf of the PDSN, and the maximum packet size MRU receivable by the PTSN is transmitted to the TE. Step (c): The AT accepts the CHAP authentication on behalf of the PDSN. Step (d): The TE accepts the CHAP authentication and the MRU of the PDSN. This message is also received by the AT on behalf of the PDSN.
    Type: Grant
    Filed: November 16, 2004
    Date of Patent: October 14, 2008
    Assignee: KDDI Corporation
    Inventors: Hidetoshi Yokota, Osamu Kobayashi, Akira Idoue
  • Publication number: 20080176560
    Abstract: A system and method for mobility support of a mobile node having a home network in a heterogeneous roaming environment is presented. The method comprises the steps of authenticating the mobile node in a visited network and obtaining an address for the mobile node in the visited network, establishing a security connection between a functional component in the visited network and an agent in the home network, creating a home address for the mobile node, and using the home address to generate a SIP signaling address, a SIP media address, and a non-SIP media address, such that SIP non-media is transmitted using the security connection to the SIP signaling address, SIP media is transmitted using the security connection to the SIP media address, and non-SIP media is transmitted using the security connection to the non-SIP media address.
    Type: Application
    Filed: December 21, 2007
    Publication date: July 24, 2008
    Inventors: Ashutosh Dutta, Subir Das, Fuchun Joe Lin, Dana Chee, Tsumehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Publication number: 20080069050
    Abstract: A mechanism by which handoff delay can be minimized while not compromising the IMS/MMD security and also protecting the media if required by certain applications is presented. One proactive method includes proactive authentication. Another proactive method includes proactive security association, such as transferring SA keys from old proxy to new proxy, or transferring keys through serving signal entities. Reactive methods include transferring SA keys from old proxy to new proxy, using either push or pull technology. Other reactive methods include transferring keys through serving signal entities using either push or pull technology.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 20, 2008
    Inventors: Ashutosh Dutta, Adhrajit Ghosh, Subir Das, Dana Chee, Kyriakos Manousakis, Funchun Lin, Shih-wei Li, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Publication number: 20080072310
    Abstract: A mechanism by which handoff delay can be minimized while not compromising the IMS/MMD security and also protecting the media if required by certain applications is presented. Methods for mitigating delay during SA re-association and mitigating the IPSec tunnel overhead for signaling and media at the Mobile Node are given. In one embodiment, SA keys can be transferred from the old P-CSCF to new P-CSCF, enabling the establishment of SAs before Mobile Node physically moves to the new subnet in a network. Proactive handover is used. In another embodiment, SA keys are transferred from S-CSCF to new P-CSCF. In this case, the SA keys are transferred to the new P-CSCF by S-CSCF through a context transfer mechanism well in advance so that SAs may be established before Mobile Node physically moves to new subnet. In another embodiment, methods for mitigating IPSec tunnel overhead are presented.
    Type: Application
    Filed: September 11, 2007
    Publication date: March 20, 2008
    Inventors: Ashutosh Dutta, Abhrajit Ghosh, Subir Das, Joesph Lin, Kyriakos Manousakis, Dana Chee, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Publication number: 20080070573
    Abstract: The present invention advantageously provides several systems and methods for solving the trombone routing issues within an IMS/MMD network. These approaches avoid trombone routing, speed up handoff, and increase the efficiency of signaling and overall performance of an IMS/MMD network. These solutions can broadly be divided into the following categories. Piggy-backing SIP registration over MIP (Split at FA); Selective Reverse Tunneling and Tunneling between FA and P-CSCF; the SIP-based mobility protocol; use of CoA during SIP registration and call up in MIPv6; Piggy-backing SIP registration when HA and S-CSCF Co-exist; Using Dynamic Home Agents in MIPv4 FA-CoA; and the Interceptor-Caching Approach.
    Type: Application
    Filed: August 31, 2007
    Publication date: March 20, 2008
    Inventors: Ashutosh Dutta, Abhrajit Ghosh, John Lee, Subir Das, Joe Lin, Kyriakos Manousakis, Tsunehiko Chiba, Hidetoshi Yokota, Akira Idoue
  • Patent number: 7236469
    Abstract: According to the present invention, there is provided a data transfer system using mobile IP in which transfer interruption is not caused even if an MH moves between FNs. A MAC bridge connected between FNs includes means responsive to an address registration request issued by an AP, for storing a combination of a MAC address of the MH and a receiving port, in a filtering DB; means for registering a relation of association of an address of a terminal accommodated in an FN with a connection port of an FN in which the terminal is accommodated, in the filtering DB; and means for referring to the filtering DB on the basis of the destination address of a frame input to each port, and transferring the frame to a predetermined port on the basis of a relation of association of the address with a port identifier.
    Type: Grant
    Filed: October 18, 2002
    Date of Patent: June 26, 2007
    Assignee: KDDI Corporation
    Inventors: Hidetoshi Yokota, Toru Hasegawa
  • Patent number: 7228131
    Abstract: A mobile host MH and its home network HN correspond to both the Internet Protocol version 4 (IPv4) and the Internet Protocol version 6 (IPv6). An authentication server (RS) is accommodated in the home network HN. A corresponding host H corresponds to the IPv6 and is accommodated in the IPv6 network. In addition, a plurality of relay servers S1, S2 and S3 corresponding to both the IPv4 and the IPv6 are accommodated in the IPv6 network. The respective S1, S2 and S3 extract an IPv6 packet by decapsulating the IPv4 packet received from the mobile host MH via the IPv4 network, and transfers the relevant IPv6 packet to the corresponding host H via the IPv6 network.
    Type: Grant
    Filed: August 31, 2005
    Date of Patent: June 5, 2007
    Assignee: KDDI Corporation
    Inventors: Hidetoshi Yokota, Akira Idoue
  • Patent number: 7203579
    Abstract: The frequency of an information signal indicative of a-vibration of a wheel detected by an acceleration sensor mounted to a wheel; or a change in the pressure of a gas in a tire detected by a pressure sensor installed in the tire, is analyzed. The band value of the obtained vibration spectrum or pressure change spectrum is detected, and a vibration level or pressure change level at the detected frequency band is compared with: a vibration level table showing the relationship between road friction coefficient ? and vibration level; or a pressure change level table showing the relationship between road friction coefficient ? and pressure change level, to estimate a road friction coefficient ?. Therefore, it is possible to estimate the value of road friction coefficient ? accurately and improve the safety of a car.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: April 10, 2007
    Assignee: Kabushiki Kaisha Bridgestone
    Inventors: Hidetoshi Yokota, Hiroshi Morinaga
  • Patent number: 7152643
    Abstract: A purpose of the present invention is to provide a rim wheel and a tire rim assembly which are capable of effectively reducing cavity resonance of a tire, and accordingly, enhancing quietness and riding comfort. A plurality of cap members 20 is arranged on an outer circumferential surface of a rim 16 in a circumferential direction thereof, diaphragms are disposed inwardly of each cap member 20, and a plurality of sub-air chambers 32 is formed between the rim 16 and the cap members 20 in a rim circumferential direction. The tire main air chamber 18 is connected to the sub-air chambers 32 through communicating holes 24 formed on the cap members 20. The sub-air chambers 32 and the communicating holes 24 constitute a Helmholtz resonance noise absorber that can absorb vibration with specified frequencies.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: December 26, 2006
    Assignee: Bridgestone Corporation
    Inventors: Hiroshi Morinaga, Hidetoshi Yokota
  • Publication number: 20060268817
    Abstract: A gateway (GW) and a plurality of foreign agents (FA) are connected in a ring-like manner, and the procedures of (1) the GW receiving an IP packet, addressed from a corresponding node CN to a mobile node MNa; (2) the GW transferring the packet to a link L1 in one direction; (3) an FA1 transferring the received packet to a link L2 in the same direction; (4) FA1 furthermore transferring the received packet to a link L4, connected to MNa, if the destination address of the received packet is already registered in the visitor list; (5) an FA2 transferring the received packet to a link L3 in the same direction; (6) FA2 furthermore ending the process as it is if the destination address of the received packet is not registered; and (7) the GW discarding the received packet.
    Type: Application
    Filed: March 17, 2004
    Publication date: November 30, 2006
    Inventors: Hidetoshi Yokota, Takeshi Kubo, Akira Idoue, Masugi Inoue, Mikio Hasegawa, Homare Murakami, Khaled Mahmud
  • Patent number: 7032436
    Abstract: The output level of vibration of a portion below the spring of a vehicle detected by a sensor, and its frequency is converted to obtain the frequency spectrum of the vibration level. Next, an operation is carried out on at least two vibration levels, at different frequency bands. The computed value is compared with a master curve showing the frequency spectrum of vibration level stored in vibration level storage to estimate the condition of a road surface so as to estimate the running state of the vehicle. Further, the running state of each tire including air pressure is detected from the vibration level of the portion below the spring to estimate the running state of the vehicle. Thereby, a multi-function sensing system is constructed for estimating the condition of a road surface or the running state of the tire with one sensor.
    Type: Grant
    Filed: June 21, 2001
    Date of Patent: April 25, 2006
    Assignee: Kabushiki Kaisha Bridgestone
    Inventors: Hidetoshi Yokota, Hiroshi Morinaga, Koji Otani
  • Publication number: 20060046713
    Abstract: A mobile host MH and its home network HN correspond to both the Internet Protocol version 4 (IPv4) and the Internet Protocol version 6 (IPv6). An authentication server (RS) is accommodated in the home network HN. A corresponding host H corresponds to the IPv6 and is accommodated in the IPv6 network. In addition, a plurality of relay servers S1, S2 and S3 corresponding to both the IPv4 and the IPv6 are accommodated in the IPv6 network. The respective S1, S2 and S3 extract an IPv6 packet by decapsulating the IPv4 packet received from the mobile host MH via the IPv4 network, and transfers the relevant IPv6 packet to the corresponding host H via the IPv6 network.
    Type: Application
    Filed: August 31, 2005
    Publication date: March 2, 2006
    Applicant: KDDI CORPORATION
    Inventors: Hidetoshi Yokota, Akira Idoue
  • Publication number: 20060009197
    Abstract: The steps and the data amount are reduced by using a PPP non-standard message to shorten a time needed for call setting, and even when a terminal or PDSN is not adapted to the non-standard message, a call setting procedure can be continued according to a PPP standard procedure. The procedure contains the steps of: establishing a wireless link between MS and PDSN, transmitting PPP standard LCP Cfg-Request from PDSN to MS, transmitting PPP non-standard AltPPP Cfg-Request from PDSN to MS, responding to AltPPP Cfg-Request and returning non-standard AltPPP Cfg-Response if MS is adapted to the non-standard message while responding to LCP Cfg-Request and returning standard LCP Cfg-Response if MS is not adapted to the non-standard message, and authenticating MS on the basis of the standard or non-standard Cfg-Response by PDSN.
    Type: Application
    Filed: June 29, 2005
    Publication date: January 12, 2006
    Applicant: KDDI CORPORATION
    Inventors: Tsunehiko Chiba, Hiroyuki Shinbo, Hidetoshi Yokota, Akira Idoue
  • Patent number: 6971427
    Abstract: A pneumatic tire includes a body having a plurality of main body cords. The tire includes an upper section above the maximum section width and a lower section below the maximum section width. The modulus of the body cords is configured to be larger in the lower section than in the upper section. This modulus ratio decreases the rolling resistance of the tire. The increased modulus in the lower section is achieved by providing intermediate body cords disposed between the main body cords. In another embodiment, the increased modulus is achieved by changing the material and/or size of the cords in the lower section.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: December 6, 2005
    Assignee: Brodgestone Firestone North American Tire, LLC
    Inventors: Carolyn W. Bernstorf, Jean-Yea Chen, Jie Jin, Masahiro Takayama, Hidetoshi Yokota
  • Publication number: 20050195782
    Abstract: The present invention includes: a procedure by which a destination FA2 recognizes the MAC address of an MN; a procedure by which the FA2 registers the MAC address of the MN in a FHReq message; a procedure by which the FA2 feeds the FHReq onto a transfer network; a procedure by which each of FAs receives the FHReq, registers an IP address corresponding to the MAC address in the FHReq when the MAC address is registered in the binding list of the FAs themselves, and feeds the IP address onto the transfer network; a procedure by which the FA2 receives the FHReq, and temporarily registers the MAC address and the IP address in the binding list of the FA2 itself; and a procedure by which the FA2 transfers data sent from an HA to the MN, based on the information which has been temporarily registered.
    Type: Application
    Filed: March 4, 2005
    Publication date: September 8, 2005
    Applicants: KDDI CORPORATION, National Institute of Information & Communications Technology., Inc. Administrative Agency
    Inventors: Hidetoshi Yokota, Takeshi Kubo, Akira Idoue, Masugi Inoue, Khaled Mahmud
  • Publication number: 20050111411
    Abstract: The present invention provide a method for call establishment over a packet exchange network which is capable of saving the time required for a call establishment of the PPP by reducing redundant steps for authentication in a SIP call, and to reduce the incoming data amount. The present invention comprising the following steps. Step (a): The TE requests the PDSN for CHAP authentication. This message is received by the AT on behalf of the PDSN. Step (b): The AT requests the TE for the CHAP authentication on behalf of the PDSN, and the maximum packet size MRU receivable by the PTSN is transmitted to the TE. Step (c): The AT accepts the CHAP authentication on behalf of the PDSN. Step (d): The TE accepts the CHAP authentication and the MRU of the PDSN. This message is also received by the AT on behalf of the PDSN.
    Type: Application
    Filed: November 16, 2004
    Publication date: May 26, 2005
    Applicant: KDDI CORPORATION
    Inventors: Hidetoshi Yokota, Osamu Kobayashi, Akira Idoue
  • Publication number: 20050099976
    Abstract: A mobile dual-stack node engages in IPv6 communication while roaming within an IPv4-only network. The node determines that it has moved and obtains a new IPv4 address. After determining that the visited network contains no IPv6-enabled components, the node communicates with a tunnel broker to obtain a care-of address and a tunnel to an IPv6 connect agent (e.g., a tunnel server). If the obtained care-of address differs from the care-of address that the node had been using prior to the move, the node sends MIPv6 binding updates to its home agent and corresponding peers. The node can optimize the handoff when it has obtained a different care-of address by sending a binding update to the connect agent comprising the previous care-of address and the current care-of address. When the connect agent receives a packet destined for the previous care-of address, it forwards the packet to the current care-of address.
    Type: Application
    Filed: September 22, 2004
    Publication date: May 12, 2005
    Inventors: Shu Yamamoto, Carl Williams, Hidetoshi Yokota, Kazuo Hashimoto
  • Publication number: 20050085987
    Abstract: The frequency of an information signal indicative of the vibration of a wheel detected by an acceleration sensor 11 mounted to a wheel 1 or the frequency of an information signal indicative of a change in the pressure of a gas in a tire detected by a pressure sensor 31 installed in the tire is analyzed by frequency analyzing means 14 (34), the band value of the obtained vibration spectrum or pressure change spectrum is detected, and a vibration level or pressure change level at the detected frequency band is compared with a vibration level table 15T showing the relationship between road friction coefficient ? and vibration level stored in vibration level storage means 15, or a pressure change level table 35T showing the relationship between road friction coefficient ? and pressure change level stored in pressure change level storage means 35 to estimate a road friction coefficient ?. Therefore, it is possible to estimate the value of road friction coefficient ? accurately and improve the safety of a car.
    Type: Application
    Filed: December 20, 2002
    Publication date: April 21, 2005
    Inventors: Hidetoshi Yokota, Hiroshi Morinaga
  • Publication number: 20050015497
    Abstract: An IPv6 enabled node finds an IPv6 connect agent by using a Domain Name System (DNS) server. The IPv6 enabled node sends a query to the DNS server and, in response, receives one or more identifiers of one or more IPv6 connect agents. In one embodiment, an identifier comprises the name of an IPv6 connect agent. In this embodiment, the IPv6 enabled node then sends a name of a desired IPv6 connect agent to the DNS server and, in response, receives the address of that IPv6 connect agent. The IPv6 enabled node is then able to engage in IPv6 communication using that IPv6 connect agent. In another embodiment, an identifier comprises the address of an IPv6 connect agent. In this embodiment, the IPv6 enabled node is able to engage in IPv6 communication using that IPv6 connect agent without any further contact with the DNS server.
    Type: Application
    Filed: December 4, 2003
    Publication date: January 20, 2005
    Inventors: Hidetoshi Yokota, Shu Yamamoto, Carl Williams, Kazuo Hashimoto
  • Publication number: 20050008032
    Abstract: A mobile IPv6 dual-stack node engages in IPv6 communication while roaming within an IPv4-only network, for example using ISATAP. First, the node determines that it has moved and obtains a new IPv4 address. After determining that the visited network contains no IPv6-enabled components, the node uses in IPv6 connect agent to engage in IPv6 communication. The node configures its care-of address using the IPv6 connect agent's routing information and the node's newly-obtained IPv4 address. In one embodiment, the node and the connect agent optimize the handoff when the node has moved but still uses the same connect agent. The node sends a binding update to the connect agent comprising the node's old care-of address and the node's new care-of address. When the connect agent receives a packet destined for the node's previous care-of address, it forwards the packet to the node's current care-of address, thereby reducing packet loss.
    Type: Application
    Filed: April 5, 2004
    Publication date: January 13, 2005
    Inventors: Shu Yamamoto, Carl Williams, Hidetoshi Yokota, Kazuo Hashimoto