Method and system for mobile communications

• US 8,331,935 B2
• Filed: 02/03/2009
• Issued: 12/11/2012
• 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: Tamura, Motoshi, Miki, Mutsumaru, Okamoto, Akiko, Kusunose, Kenya, Uchikoshi, Akihiro, Igarashi, Daisuke, Yamagata, Katsuhiko, Sato, Takaaki, Hagiwara, Junichiro, Watanabe, Yasuyuki, Hamajima, Takuya, Hata, Masafumi, Ishikawa, Nobutaka, Yasuda, Yoshiyuki, Yunoki, Kazufumi, Uchiyama, Nobuhide
• Primary Examiner(s): Doan, Kiet
• Assistant Examiner(s): Vu, Michael T
• Application Number:
  US12/364,766
• Publication Number:
  US 20090149182A1
• Time in Patent Office: 1,407 Days
• Field of Search: 455/415, 455/414, 455463-464, 455/450, 455455-456, 455/561, 370/331, 370334-335, 370/342
• US Class Current: 455/436
• 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 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.

Claims

1. A method for conducting a plurality of simultaneous calls, comprising computer executable steps executed by a processor of a mobile station to implement:

conducting a first call at a frequency band via a diversity branch structure including a plurality of CDMA access channels established respectively with a plurality of base stations for diversity handover; and

responsive to a second call request, concurrently with conducting the first call, initiating to conduct a second call at the same frequency band via a plurality of CDMA access channels established patterned after the diversity branch structure, using the plurality of base stations.

2. A mobile station capable of conducing a plurality of simultaneous calls, comprising a processor and a memory that stores programs executable by the processor to:

conduct a first call at a frequency band via a diversity branch structure including a plurality of CDMA access channels established respectively with a plurality of base stations for diversity handover; and

responsive to a second call request, concurrently with conducting the first call, initiate to conduct a second call at the same frequency band via a plurality of CDMA access channels established patterned after the diversity branch structure, using the plurality of base stations.

3. A base station controller for controlling a branch structure and a frequency band, comprising a processor and a memory that stores programs executable by the processor to:

serve a first call at a frequency band via a diversity branch structure including a plurality of CDMA access channels established respectively with a plurality of base stations for diversity handover; and

responsive to a second call request, establish a plurality of CDMA access channels patterned after the diversity branch structure, to serve a second call at the same frequency band, using the plurality of base stations, concurrently with serving the first call.

4. A method for conducting a plurality of simultaneous calls, comprising computer executable steps executed by a processor of a mobile station to implement:

conducting a first call via a branch structure including at least one first CDMA access channel established with at least one base station;

responsive to a second call request, continuing conducting the first call via a modified branch structure established for diversity handover; and

concurrently with conducting the first call, initiating to conduct a second call via at least one second CDMA access channel established patterned after the modified branch structure.

5. The method according to claim 4, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station in addition to the at least one first CDMA access channel to the at least one base station.

6. The method according to claim 4, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station which replaces the at least one first CDMA channel to the at least one base station.

7. The method according to claim 6, wherein the modified branch structure operates at a frequency band different from that for the branch structure before modification.

8. A mobile station capable of conducting a plurality of simultaneous calls, comprising a processor and a memory that stores programs executable by the processor to:

conduct a first call via a branch structure including at least one first CDMA access channel established with at least one base station;

responsive to a second call request, continue conducting the first call via a modified branch structure established for diversity handover; and

concurrently with conducting the first call, initiate to conduct a second call via at least one second CDMA access channel established, patterned after the modified branch structure.

9. The mobile station according to claim 8, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station in addition to the at least one first CDMA access channel to the at least one base station.

10. The mobile station according to claim 8, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station which replaces the at least one first CDMA channel to the at least one base station.

11. The mobile station according to claim 10, wherein the modified branch structure operates at a frequency band different from that for the branch structure before modification.

12. A base station controller for controlling a branch structure and a frequency band, comprising a processor and a memory that stores programs executable by the processor to:

serve a first call via a branch structure including at least one first CDMA access channel established with at least one base station;

responsive to a second call request, modifying the branch structure during diversity handover to continue serving the first call; and

concurrently with serving the first call, establish at least one second CDMA access channel, patterned after a modified branch structure, to serve a second call via the at least one second CDMA access channel.

13. The base station controller according to claim 12, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station in addition to the at least one first CDMA access channel to the at least one base station.

14. The base station controller according to claim 12, wherein the modified branch structure includes at least one third CDMA access channel established with at least one other base station which replaces the at least one first CDMA channel to the at least one base station.

15. The base station controller according to claim 14, wherein the modified branch structure operates at a frequency band different from that for the branch structure before modification.