Patents by Inventor Tomoyuki Ohtani
Tomoyuki Ohtani 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: 8090373Abstract: A mobile station for communicating with base stations simultaneously in diversity handover. The mobile station monitors radio condition quality corresponding to a plurality of branches, selects one or more addition branch candidates based on the monitored radio condition quality. The mobile station arranges the addition branch candidates in order of the monitored radio condition quality; notifies a center of information on said plurality of branches including said addition branch candidates, the addition branch candidates being notified in the arranged order. Alternatively, the mobile station obtains a relative value of each of the addition branch candidates indicative of order of precedence to be used for the diversity handover based on the monitored radio condition quality of said addition branch candidates; and notifies a center of information on said plurality of branches including said addition branch candidates and their relative values.Type: GrantFiled: October 25, 2010Date of Patent: January 3, 2012Assignee: NTT Docomo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 8064908Abstract: A mobile station for communicating with base stations simultaneously in diversity handover. The mobile station monitors radio condition quality corresponding to a plurality of branches, selects one or more addition branch candidates based on the monitored radio condition quality. The mobile station arranges the addition branch candidates in order of the monitored radio condition quality; notifies a center of information on said plurality of branches including said addition branch candidates, the addition branch candidates being notified in the arranged order. Alternatively, the mobile station obtains a relative value of each of the addition branch candidates indicative of order of precedence to be used for the diversity handover based on the monitored radio condition quality of said addition branch candidates; and notifies a center of information on said plurality of branches including said addition branch candidates and their relative values.Type: GrantFiled: June 18, 2008Date of Patent: November 22, 2011Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20110032905Abstract: A mobile station for communicating with base stations simultaneously in diversity handover. The mobile station monitors radio condition quality corresponding to a plurality of branches, selects one or more addition branch candidates based on the monitored radio condition quality. The mobile station arranges the addition branch candidates in order of the monitored radio condition quality; notifies a center of information on said plurality of branches including said addition branch candidates, the addition branch candidates being notified in the arranged order. Alternatively, the mobile station obtains a relative value of each of the addition branch candidates indicative of order of precedence to be used for the diversity handover based on the monitored radio condition quality of said addition branch candidates; and notifies a center of information on said plurality of branches including said addition branch candidates and their relative values.Type: ApplicationFiled: October 25, 2010Publication date: February 10, 2011Applicant: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 7873014Abstract: A handover method for controlling communication between a mobile station and base station(s) in a wireless communication system. The method includes measuring signal qualities transmitted from the base station(s), the measured signal qualities including a measured quality of a signal received from a certain base station; identifying the base station as an addition candidate based on the measured quality exceeding an addition threshold; thereafter detecting that the measured quality of the signal received from the addition candidate has further exceeded an active threshold which is greater than the addition threshold. The active threshold is determined in accordance with a quality of a signal transmitted from one or more active base stations. In response, the base stations are notified of information about the addition candidate; and a handover process is performed on the bases on this information.Type: GrantFiled: October 30, 2007Date of Patent: January 18, 2011Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 7570950Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: GrantFiled: October 31, 2006Date of Patent: August 4, 2009Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20090011766Abstract: A mobile station for communicating with base stations simultaneously in diversity handover. The mobile station monitors radio condition quality corresponding to a plurality of branches, selects one or more addition branch candidates based on the monitored radio condition quality. The mobile station arranges the addition branch candidates in order of the monitored radio condition quality; notifies a center of information on said plurality of branches including said addition branch candidates, the addition branch candidates being notified in the arranged order. Alternatively, the mobile station obtains a relative value of each of the addition branch candidates indicative of order of precedence to be used for the diversity handover based on the monitored radio condition quality of said addition branch candidates; and notifies a center of information on said plurality of branches including said addition branch candidates and their relative values.Type: ApplicationFiled: June 18, 2008Publication date: January 8, 2009Applicant: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 7403777Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: GrantFiled: March 26, 2004Date of Patent: July 22, 2008Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 7403489Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.Type: GrantFiled: July 3, 2007Date of Patent: July 22, 2008Assignee: NTT Mobile Communications Network Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
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Patent number: 7362715Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.Type: GrantFiled: September 8, 2005Date of Patent: April 22, 2008Assignee: NTT Mobile Comunications Network, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
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Publication number: 20080056197Abstract: A handover method for controlling communication between a mobile station and base station(s) in a wireless communication system. The method includes measuring signal qualities transmitted from the base station(s), the measured signal qualities including a measured quality of a signal received from a certain base station; identifying the base station as an addition candidate based on the measured quality exceeding an addition threshold; thereafter detecting that the measured quality of the signal received from the addition candidate has further exceeded an active threshold which is greater than the addition threshold. The active threshold is determined in accordance with a quality of a signal transmitted from one or more active base stations. In response, the base stations are notified of information about the addition candidate; and a handover process is performed on the bases on this information.Type: ApplicationFiled: October 30, 2007Publication date: March 6, 2008Applicant: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20070259666Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.Type: ApplicationFiled: July 3, 2007Publication date: November 8, 2007Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
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Patent number: 7289809Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: GrantFiled: February 2, 2006Date of Patent: October 30, 2007Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20070058589Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: ApplicationFiled: October 31, 2006Publication date: March 15, 2007Applicant: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20060171328Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.Type: ApplicationFiled: September 8, 2005Publication date: August 3, 2006Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
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Publication number: 20060128386Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: ApplicationFiled: February 2, 2006Publication date: June 15, 2006Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: 7010302Abstract: An address structure in mobile communications network facilitating routing of a packet. At the initial position of the address, is located a prefix or the like indicating the type of the address structure, which indicates the present mobile communications network system, for example. At the next position, a location address (LA) is located characterizing the present invention. The location address is usually placed at the position of a subnetwork address. The location address (LA) is provided for each mobile switching system, and constitutes part of an IP address of a user using a mobile station under the control of the mobile switching system. At the final position, is located a user identifier (user ID) which is used for identifying a user, and is provided uniquely for each user.Type: GrantFiled: May 7, 1999Date of Patent: March 7, 2006Assignee: NTT DoCoMo, Inc.Inventors: Akihisa Nakajima, Hiroshi Nakamura, Teruki Niwa, Yukichi Saito, Tomoyuki Ohtani, Hideo Morita
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Patent number: 6977903Abstract: Disclosed is a mobile communication system including a network constituted of at least one switching center and a plurality of base stations, and a mobile station which communicates with the base stations simultaneously. The system permits varying transmission delay between the switching center and the base stations according to the type of services available to the mobile station. The object of the present invention is to propose a communication which permits varying transmission delay according to the type of service currently employed, and to promptly recover a synchronization state even if an out-of-sync state happens. To attain the object, a memory means (mobile switching center processor 32) stores transmission delay characteristics corresponding to services which are available to the mobile station.Type: GrantFiled: December 25, 1997Date of Patent: December 20, 2005Assignee: NTT Mobile Communications Network, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Satoh, Hiroki Morikawa, Fumiaki Ishino
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Patent number: 6807420Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: GrantFiled: March 7, 2003Date of Patent: October 19, 2004Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Publication number: 20040180662Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: ApplicationFiled: March 26, 2004Publication date: September 16, 2004Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato
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Patent number: RE43296Abstract: A branch candidate selecting method by a mobile station and a diversity handover control method on a network side in DHO performance are provided which consider a maximum cable branch number and maximum radio branch number of the mobile station, when the mobile station detects the plurality of addition branch candidates and deletion branch candidates. The mobile station inserts a plurality of addition branch candidates and deletion branch candidates, that is, all the DHO candidates into one handover trigger signal, and notifies the network. The addition branch candidates are put into addition information parameters in the handover trigger signal, and the deletion branch candidates are put into deletion information parameters. To simplify processing on the network side, the network side separates the addition branch candidates from the deletion branch candidates, and carries out sequential processing of them independently.Type: GrantFiled: October 1, 2009Date of Patent: April 3, 2012Assignee: NTT DoCoMo, Inc.Inventors: Tomoyuki Ohtani, Motoshi Tamura, Takaaki Sato