Method and system for mobile communications

• US 20080108356A1
• Filed: 05/30/2007
• Published: 05/08/2008
• Est. Priority Date: 04/24/1997
• Status: Active Grant

• Current Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Watanabe, Yasuyuki, Sato, Takaaki, Hata, Masafumi, Tamura, Motoshi, Uchiyama, Nobuhide, Igarashi, Daisuke, Uchikoshi, Akihiro, Okamoto, Akiko, Ishikawa, Nobutaka, Hagiwara, Junichiro, Miki, Mutsumaru, Hamajima, Takuya, Yunoki, Kazufumi, Yasuda, Yoshiyuki, Kusunose, Kenya, Yamagata, Katsuhiko
• Granted Patent: US 7,792,531 B2
• Time in Patent Office: Days
• US Class Current: 455/445
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/12 Access point controller devices

Abstract

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. Additionally, 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. Therefore, the mobile communications system is suitable for transmission of various sorts of data in accordance with the development of multimedia.

Claims

1-99. -99. (canceled)

100. A diversity handover controller communicating with a mobile terminal through a plurality of base stations, comprising:

a call attempt receiver configured to receive via one of the plurality of base stations a call attempt from the mobile terminal having no access link established with any of the plurality of base stations;

a handover setup requester configured to initiate a handover setup procedure by sending a handover setup request among the plurality of base stations;

a confirmation sender configured to send an acknowledgement to the handover set up request from one or more base stations which have completed the handover setup procedure;

a branch information reporter configured to send the mobile station branch information regarding more than one base station among the plurality of base stations which is accessible to establish an access link with the mobile terminal for a diversity handover.

102. A diversity handover controller according to claim 101, wherein the plurality of base stations are functional entities.

103. A diversity handover controller according to claim 101, wherein the call attempt is associated with a pilot report of strong pilot signals.

104. A diversity handover controller according to claim 103, wherein the handover setup requester sends the handover setup request to one or more base stations, using the pilot report.

105. A diversity handover controller according to claim 104, wherein the handover setup requester sends the handover setup request to the one or more base stations identified in the pilot report.

106. A diversity handover controller according to claim 101, wherein the handover setup requester sends the handover setup request from the one of the plurality of base stations.

107. A diversity handover controller according to claim 101, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

108. A diversity handover controller according to claim 107, wherein the branch information reporter sends the branch information from the one of the plurality of base stations.

109. A diversity handover controller according to claim 108, further comprising a sync signal receiver configured to receive a sync signal for establishing an access link from the mobile terminal, which has received the branch information.

110. A diversity handover controller according to claim 109, further comprising a setup completion reporter configured to send an acknowledgement of completing establishment of access link.

111. A diversity handover method implemented in a diversity handover controller communicating with a mobile terminal through a plurality of base stations, comprising:

receiving a call attempt via one of the plurality of base stations from the mobile terminal having no access link established with any of the plurality of base stations;

initiating a handover setup procedure by sending a handover setup request among the plurality of base stations;

sending an acknowledgement to the handover set up request from one or more base stations which have completed the handover setup procedure; and

sending the mobile station branch information regarding more than one base station among the plurality of base stations which is accessible to establish an access link with the mobile terminal for a diversity handover.

112. A method according to claim 111, wherein the plurality of base stations are functional entities.

113. A method according to claim 111, wherein the call attempt is associated with a pilot report of strong pilots signals.

114. A method according to claim 113, wherein sending a handover setup request comprises sending a handover setup request to one or more base stations, using the pilot report.

115. A method according to claim 114, wherein sending a handover setup request comprises sending a handover setup request to one or more base stations identified in the pilot report.

116. A method according to claim 111, wherein sending a handover setup request comprises sending a handover setup request from the one of the plurality of base stations.

117. A method according to claim 111, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

118. A method according to claim 117, wherein sending branch information comprises sending branch information from the one of the plurality of base stations.

119. A method according to claim 118, further comprising receiving a sync signal for establishment of a radio access link from the mobile terminal, which has received the branch information.

120. A method according to claim 119, further comprising sending an acknowledgement of completing establishment of radio access link.

121. A mobile terminal connectible to a plurality of base stations for communication therewith, comprising:

a call generator configured to send out a call attempt absent an access link established with any of the plurality of base stations; and

a receiver configured to receive branch information regarding more than one base station among the plurality of base stations accessible to establish at least one access link with the mobile terminal for a diversity handover.

122. A mobile terminal according to claim 121, wherein the call attempt is associated with a pilot report of strong pilot signals, and wherein the more than one base station is identified in the pilot report.

123. A mobile terminal according to claim 121, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

124. A mobile terminal according to claim 123, further comprising a sync signal sender configured to send out a sync signal for establishing at least one access link with the more than one base station.

125. A diversity handover method implemented in a mobile terminal connectible to a plurality of base stations for communication therewith, comprising:

sending out a call attempt absent an access link established with any of the plurality of base stations; and

receiving branch information regarding more than one base station among the plurality of base stations which is accessible to establish at least one access link with the mobile terminal for a diversity handover.

126. A diversity handover method according to claim 125, wherein sending out a call attempt comprises sending out a pilot report of strong pilot signals, and wherein the more than one base station is identified in the pilot report.

127. A diversity handover method according to claim 125, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

128. A diversity handover method according to claim 127, further comprising sending out a sync signal for establishing at least one access link with the more than one base station.