Patents by Inventor Masafumi Hata
Masafumi Hata 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: 8542835Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 5, 2009Date of Patent: September 24, 2013Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8331935Abstract: When a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used.Type: GrantFiled: February 3, 2009Date of Patent: December 11, 2012Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8275133Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: March 30, 2006Date of Patent: September 25, 2012Assignee: NTT Docomo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8259675Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 4, 2009Date of Patent: September 4, 2012Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 8185158Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: April 9, 2009Date of Patent: May 22, 2012Assignee: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7953414Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: January 28, 2009Date of Patent: May 31, 2011Assignee: NTT DocomoInventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7907730Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 6, 2009Date of Patent: March 15, 2011Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7792531Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: May 30, 2007Date of Patent: September 7, 2010Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7664507Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: April 6, 2006Date of Patent: February 16, 2010Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7630716Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: February 28, 2007Date of Patent: December 8, 2009Assignee: NTT DoCoMo, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7577435Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: April 5, 2006Date of Patent: August 18, 2009Assignee: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090197646Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: April 9, 2009Publication date: August 6, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090191924Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: January 28, 2009Publication date: July 30, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090190761Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: February 6, 2009Publication date: July 30, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090154702Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: February 5, 2009Publication date: June 18, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090149181Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: January 30, 2009Publication date: June 11, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090149182Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: February 3, 2009Publication date: June 11, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20090141687Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: February 4, 2009Publication date: June 4, 2009Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Patent number: 7383045Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: GrantFiled: March 28, 2006Date of Patent: June 3, 2008Assignee: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama
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Publication number: 20080108356Abstract: When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover.Type: ApplicationFiled: May 30, 2007Publication date: May 8, 2008Applicant: NTT Mobile Communications Network, Inc.Inventors: Motoshi Tamura, Mutsumaru Miki, Akiko Okamoto, Kenya Kusunose, Akihiro Uchikoshi, Daisuke Igarashi, Katsuhiko Yamagata, Takaaki Sato, Junichiro Hagiwara, Yasuyuki Watanabe, Takuya Hamajima, Masafumi Hata, Nobutaka Ishikawa, Yoshiyuki Yasuda, Kazufumi Yunoki, Nobuhide Uchiyama