Method and system for mobile communications

• US 7,792,531 B2
• Filed: 05/30/2007
• Issued: 09/07/2010
• Est. Priority Date: 04/24/1997
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (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
• Primary Examiner(s): Le; Danh C
• Application Number:
  US11/807,825
• Publication Number:
  US 20080108356A1
• Time in Patent Office: 1,196 Days
• Field of Search: 455/439, 455/438, 455/436, 370/331
• US Class Current: 455/439
• 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 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. 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.

2. A diversity handover controller according to claim 1, wherein the plurality of base stations are functional entities.

3. A diversity handover controller according to claim 1, wherein the call attempt is associated with a pilot report of strong pilot signals.

4. A diversity handover controller according to claim 3, wherein the handover setup requester sends the handover setup request to one or more base stations, using the pilot report.

5. A diversity handover controller according to claim 4, wherein the handover setup requester sends the handover setup request to the one or more base stations identified in the pilot report.

6. A diversity handover controller according to claim 1, wherein the handover setup requester sends the handover setup request from the one of the plurality of base stations.

7. A diversity handover controller according to claim 1, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

8. A diversity handover controller according to claim 7, wherein the branch information reporter sends the branch information from the one of the plurality of base stations.

9. A diversity handover controller according to claim 8, 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.

10. A diversity handover controller according to claim 9, further comprising a setup completion reporter configured to send an acknowledgement of completing establishment of access link.

11. 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.

12. A method according to claim 11, wherein the plurality of base stations are functional entities.

13. A method according to claim 11, wherein the call attempt is associated with a pilot report of strong pilots signals.

14. A method according to claim 13, wherein sending a handover setup request comprises sending a handover setup request to one or more base stations, using the pilot report.

15. A method according to claim 14, wherein sending a handover setup request comprises sending a handover setup request to one or more base stations identified in the pilot report.

16. A method according to claim 11, wherein sending a handover setup request comprises sending a handover setup request from the one of the plurality of base stations.

17. A method according to claim 11, wherein the branch information comprises a request to establish an access link with the more than one base station for the diversity handover.

18. A method according to claim 17, wherein sending branch information comprises sending branch information from the one of the plurality of base stations.

19. A method according to claim 18, further comprising receiving a sync signal for establishment of a radio access link from the mobile terminal, which has received the branch information.

20. A method according to claim 19, further comprising sending an acknowledgement of completing establishment of radio access link.