Patents by Inventor Takatoshi Okagawa
Takatoshi Okagawa 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).
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Patent number: 9326180Abstract: Even if a failure has occurred in core network equipment in a state in which bearers are established between a large number of UEs and a packet data network, congestion in the network is avoided. A mobile communication method according to the present invention includes steps of transmitting, by an MME, to transmit a “PDN Disconnection Request/Detach Request” including barring time to a UE when the MME disconnects a bearer between the UE and the packet data network due to a predetermined reason such as a failure in a S-GW/P-GW or the MME in a state in which the bearer is established, and barring, by the UE, a mobile originating call directed to the packet data network for the barring time.Type: GrantFiled: October 1, 2012Date of Patent: April 26, 2016Assignee: NTT DOCOMO, INC.Inventors: Itsuma Tanaka, Takatoshi Okagawa, Masahiro Sawada, Tomoki Shibahara, Keisuke Suzuki
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Publication number: 20140254363Abstract: Even if a failure has occurred in core network equipment in a state in which bearers are established between a large number of UEs and a packet data network, congestion in the network is avoided. A mobile communication method according to the present invention includes steps of transmitting, by an MME, to transmit a “PDN Disconnection Request/Detach Request” including barring time to a UE when the MME disconnects a bearer between the UE and the packet data network due to a predetermined reason such as a failure in a S-GW/P-GW or the MME in a state in which the bearer is established, and barring, by the UE, a mobile originating call directed to the packet data network for the barring time.Type: ApplicationFiled: October 1, 2012Publication date: September 11, 2014Applicant: NTT DOCOMO, INC.Inventors: Itsuma Tanaka, Takatoshi Okagawa, Masahiro Sawada, Tomoki Shibahara, Keisuke Suzuki
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Patent number: 8611892Abstract: A mobile communication network system (1) is disclosed. The network system comprises a transport network (30) including a plurality of routers (31), and a network control apparatus (20) for controlling mobility of a mobile node (40, MN1), characterized in that the network control apparatus (20) comprises a mobility managing unit (LRM1) for managing information (CDT) of a correspondent node (41, MN2) communicating with the mobile node (40, MN1); the mobility managing unit (LRM1) comprises a boundary router detecting unit for detecting that the mobile node (MN1) moves and reaches a boundary of a router (AR2) managed by the mobility managing unit (LRM1) itself; and a correspondent node information forwarding unit for forwarding the information (CDT) of the correspondent node (MN2) to a neighbor mobility managing unit (LRM2) having a similar structure, when it is detected that the mobile node (MN1) reaches a boundary of a router (AR2) managed by the mobility managing unit (LRM1) itself.Type: GrantFiled: March 4, 2005Date of Patent: December 17, 2013Assignee: NTT DoCoMo, Inc.Inventors: Atsushi Iwasaki, Takatoshi Okagawa
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Patent number: 8135005Abstract: The object of the present invention is provide a communication control system which can realize a dynamic routing control in units of flows without changing the conventional routing protocol. The routing controller comprises an address information provision requester configured to request the first router to provide address conversion information in accordance with the received predetermined trigger and an address conversion information processing requester configured to request the second router to perform a predetermined processing related to the address conversion information acquired from the first router.Type: GrantFiled: November 5, 2003Date of Patent: March 13, 2012Assignee: NTT DoCoMo, Inc.Inventors: Takatoshi Okagawa, Manhee Jo, Katsutoshi Nishida, Noriteru Shinagawa
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Patent number: 7826461Abstract: The packet switching system for transmitting and receiving a packet via a packet switching network 100, which comprises a plurality of routing tables (#0, #1, #2 . . . ), each of which has been generated by a unique routing policy, stored in the routing apparatuses deployed at the border, at the origin or at the end of the respective routing domains, an identifier (RTI) inserted in the packet to specify the routing tables, and an identifier changer to change a value of the identifier on the packet switching network 100. The routing apparatus selects one of the routing tables (#0, #1, #2 . . . ) according to the RTI in the received packet and transfers the packet to a destination that is specified by the selected routing table.Type: GrantFiled: September 10, 2007Date of Patent: November 2, 2010Assignee: NTT DoCoMo, Inc.Inventors: Takatoshi Okagawa, Yasuhisa Hayashi, Manhee Jo, Takeshi Ihara
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Patent number: 7751819Abstract: A mobile communication system of the present invention includes a handover control unit and a packet transfer network, which are independent of each other. The handover control unit selects a handover control system in accordance with a QoS. The handover control unit issues an instruction to the packet transfer network in accordance with the selected handover control system.Type: GrantFiled: September 6, 2005Date of Patent: July 6, 2010Assignee: NTT DoCoMo, Inc.Inventors: Shin-ichi Isobe, Kenji Nishimura, Takatoshi Okagawa
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Patent number: 7715346Abstract: A mobile terminal according to the present invention judges, based on a router advertisement transmitted from an access router, whether handover is to be executed between access points connected to the access router, and transmits a link moving notification, which indicates that handover is executed under control of the access router, to the access router. Further, the access router updates only routing information based on the received link moving notification.Type: GrantFiled: May 6, 2009Date of Patent: May 11, 2010Assignee: NTT DoCoMo, Inc.Inventors: Takayuki Ohbayashi, Takatoshi Okagawa, Katsutoshi Nishida
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Publication number: 20100098022Abstract: The invention relates to a method, apparatus and system to preferably route a packet via an IP network, and more particularly to a routing entity having a buffer storing packets from/to a mobile entity. An initiation unit (500, 121) initiates a distribution of a routing topology change. A buffer unit (520) buffers a packet from/to the mobile entity (102) until the completion of the distribution. A release unit (502) releases the buffered packet after the completion.Type: ApplicationFiled: August 9, 2006Publication date: April 22, 2010Inventors: Csaba Keszei, Zoltan Turanyi, Takatoshi Okagawa, Atsushi Iwasaki
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Publication number: 20090225724Abstract: A mobile terminal according to the present invention judges, based on a router advertisement transmitted from an access router, whether handover is to be executed between access points connected to the access router, and transmits a link moving notification, which indicates that handover is executed under control of the access router, to the access router. Further, the access router updates only routing information based on the received link moving notification.Type: ApplicationFiled: May 6, 2009Publication date: September 10, 2009Applicant: NTT DoCoMo, IncInventors: Takayuki OHBAYASHI, Takatoshi OKAGAWA, Katsutoshi NISHIDA
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Patent number: 7548524Abstract: A mobile terminal MN1 according to the present invention judges, based on a router advertisement transmitted from an access router AR1, whether handover is to be executed between access points (APs) connected to the access router AR1, and transmits a link moving notification, which indicates that handover is executed under control of the access router AR1, to the access router AR1. Further, the access router AR1 updates only routing information based on the received link moving notification.Type: GrantFiled: September 8, 2004Date of Patent: June 16, 2009Assignee: NTT DoCoMo, Inc.Inventors: Takayuki Ohbayashi, Takatoshi Okagawa, Katsutoshi Nishida
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Patent number: 7545785Abstract: A mobile communication system comprises an access router configured to assign a routing address to a transient address when receiving a user data packet including the transient address is set to a source address from a mobile terminal connecting to the access router and store a correspondence between the transient address and the routing address, and a management device configured to judge whether or not a handover is carried out by judging whether or not an existing routing address assigned to the mobile terminal by other access router than the access router to which the mobile terminal connects exists, based on a unique identifier of the mobile terminal.Type: GrantFiled: June 7, 2005Date of Patent: June 9, 2009Assignee: NTT DoCoMo, Inc.Inventors: Katsutoshi Nishida, Shinichi Isobe, Takatoshi Okagawa
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Patent number: 7535896Abstract: The routing control system 100 according to the present invention comprises a control server 1 as the control system, and routers 10-60 as the transfer system. The control server 1 receives the temporary routing control table which is transmitted from the routers 10-60, and stores this temporary routing control table in the routing control table DB 6 as the routing control table of the router which is the transmission source. This routing control table is updated as needed when a predetermined time has elapsed from the previous update. The control server 1 refers to the data in the routing control table DB 6 constructed in this way, and performs the routing control of packets which pass through each router 10-60 on the network.Type: GrantFiled: October 22, 2003Date of Patent: May 19, 2009Assignee: NTT DoCoMo, Inc.Inventors: Manhee Jo, Katsutoshi Nishida, Takatoshi Okagawa, Noriteru Shinagawa
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Patent number: 7526569Abstract: The problems of an additional load to an AR having the function of transferring a packet, a BR functioning as a border relay device, and an address management server, a packet loss due to an unnecessary inquiry to the management server, an increasing delay of a packet transfer, etc. can be reduced. According to the address identification information for identification of the type of an address, routers determine to which type the address assigned to a given packet belongs, a terminal identification address for identification of a source terminal and a destination terminal, a packet transfer address for transfer of the packet to another router, or an address requiring no address conversion. Thus, an address conversion network connected to an external IP network can be realized, an increased load by an inquiry about an erroneous address, etc. and a packet loss and delay due to an unnecessary inquiry can be reduced.Type: GrantFiled: April 27, 2004Date of Patent: April 28, 2009Assignee: NTT DoCoMo, Inc.Inventors: Katsutoshi Nishida, Takatoshi Okagawa, Manhee Jo
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Patent number: 7466674Abstract: A mobile communication control method includes: converting a first address of a destination mobile terminal which is included in a packet as a destination address, to a second address of the destination mobile terminal which is associated with the first address of the destination mobile terminal, in a source router; and converting the second address of the destination mobile terminal which is included in the received packet as a destination address, to the first address of the destination mobile terminal which is associated with the second address of the destination mobile terminal, in a destination router.Type: GrantFiled: September 22, 2003Date of Patent: December 16, 2008Assignee: NTT DoCoMo, Inc.Inventors: Takatoshi Okagawa, Manhee Jo, Katsutoshi Nishida, Noriteru Shinagawa
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Patent number: 7417969Abstract: Determining a cross over router on the occasion of a migration of a mobile terminal connected to a network during communication in the network. A path control device receives path control information from each router in the network and stores the information as a path control table. Then, a pre-migration path between the mobile terminal and the correspondent terminal is recognized and, on the occasion of a migration of a mobile terminal, the path control device predicts a post-migration path between the mobile terminal and the correspondent terminal. The path control device then compares the pre-migration path and the post-migration path to derive as a common part, and a router closest to the mobile terminal in the common part is determined as a cross over router.Type: GrantFiled: January 15, 2004Date of Patent: August 26, 2008Assignee: NTT DoCoMo, Inc.Inventors: Manhee Jo, Shinichi Isobe, Katsutoshi Nishida, Takatoshi Okagawa
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Patent number: 7408879Abstract: A router includes a clock configured to be synchronous to a transmission terminal that transmits a data packet; a comparator configured to compare a delay time of the data packet with an acceptable delay time of the data packet based on the time obtained from the clock; and a packet processing unit configured to either transfer or discard the data packet based on the comparison result of the comparator.Type: GrantFiled: December 11, 2002Date of Patent: August 5, 2008Assignee: NTT DoCoMo, Inc.Inventors: Manhee Jo, Yasuhisa Hayashi, Takatoshi Okagawa, Takeshi Ihara
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Patent number: 7324490Abstract: A relay device acquires and stores address binding information indicating correspondence between a static communication address and a dynamic communication address of a mobile terminal which is linked to the relay device. The relay device also stores address binding information of other mobile terminals to which packets are sent from the source terminal. A management server stores the address binding information pertaining to the source terminal, and also stores the communication status information of the other mobile terminals with which the terminal is communicating. When the terminal terminates communication, the relay device and the server delete the address binding information pertaining to the source terminal by cooperating with each other.Type: GrantFiled: February 17, 2004Date of Patent: January 29, 2008Assignee: NTT DoCoMo, Inc.Inventors: Katsutoshi Nishida, Takatoshi Okagawa, Manhee Jo
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Publication number: 20080013549Abstract: The packet switching system for transmitting and receiving a packet via a packet switching network 100, which comprises a plurality of routing tables (#0, #1, #2 . . . ), each of which has been generated by a unique routing policy, stored in the routing apparatuses deployed at the border, at the origin or at the end of the respective routing domains, an identifier (RTI) inserted in the packet to specify the routing tables, and an identifier changer to change a value of the identifier on the packet switching network 100. The routing apparatus selects one of the routing tables (#0, #1, #2 . . . ) according to the RTI in the received packet and transfers the packet to a destination that is specified by the selected routing table.Type: ApplicationFiled: September 10, 2007Publication date: January 17, 2008Applicant: NTT DoCoMo, IncInventors: Takatoshi OKAGAWA, Yasuhisa Hayashi, Manhee Jo, Takeshi Ihara
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Publication number: 20070291754Abstract: A packet communications system and a transfer device which allow a network control function to be changed at low cost flexibly. The network manager includes an instructor for transmitting instruction information to the plurality of transfer devices, the instruction information indicating a packet ID (terminal ID) and a control function (function ID) executed on the packet. The transfer device includes an executer for executing a predetermined control function on the packet, a first memory for storing the packet ID associated with the executer of the control function executed on the packet, a manager for updating the first memory in accordance with the instruction information received from the network manager, and an internal transfer for transferring the received packet to the executer associated with the packet in the first memory.Type: ApplicationFiled: August 21, 2007Publication date: December 20, 2007Applicant: NTT DoCoMo, Inc.Inventors: Takatoshi OKAGAWA, Takeshi Ihara, Masami Yabusaki
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Publication number: 20060068847Abstract: A new mobile control system, a mobile control method, a mobile control device and a mobile control program, which are capable of achieving efficient control by integrating a plurality of mobile control services when simultaneously applying a plurality of mobile control services to mobile terminals or exchange networks, are provided. The mobile control method manages and controls an exchange network N communicably connecting a plurality of mobile terminals 10, and when a plurality of mobile control services regarding the same mobile terminal 10 is performed on the exchange network N either simultaneously or within a predetermined time, integrates the various mobile control services, thereby achieving economic and efficient control.Type: ApplicationFiled: September 2, 2005Publication date: March 30, 2006Applicant: NTT DoCoMo, Inc.Inventors: Kenji Nishimura, Shin-ichi Isobe, Takatoshi Okagawa