Mobile station transfer control system, cell transfer control method, mobile station, cell transfer control method at mobile station, cell transfer control program, control apparatus, and allocating method of communication resources

• US 7,039,413 B2
• Filed: 10/23/2002
• Issued: 05/02/2006
• Est. Priority Date: 10/24/2001
• Status: Expired due to Term

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Masuda, Masafumi, Yazaki, Hidetoshi, Maebara, Akihiro, Nagano, Takashi, Niiyama, Hiromu
• Primary Examiner(s): Gesesse, Tilahun
• Assistant Examiner(s): Lee, John J.
• Application Number:
  US10/277,755
• Publication Number:
  US 20030087637A1
• Time in Patent Office: 1,287 Days
• Field of Search: 455/412.1, 455/412.2, 455/422.1, 455/446, 455/507, 455/517, 455/550.1, 455/437, 455/436, 455/442, 455/525, 455/435.1, 455/435.2, 455/434, 455/443, 455/444, 455/524
• US Class Current: 455/446
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/1443 between licensed networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

While a plurality of cellular mobile communication systems have their respective service areas regionally overlapping each other in part, a mobile station is configured to perform a standby for calling or communication while selecting one of the plural systems in the overlapping areas, and is arranged as follows: the mobile station preliminarily stores cell information notified of by a base station and indicating whether the mobile station is transferable to each surrounding cell while maintaining the current system; when the arrival of transfer timing to a surrounding cell is detected, the mobile station extracts the information about the pertinent cell and judges whether the surrounding cell is a transferable cell, based on the cell information; when the surrounding cell is a transferable cell, the mobile station transfers to the surrounding cell; when the surrounding cell is not a transferable cell, the mobile station directly transfers to a cell of a different system. This makes it feasible to decrease communication down time and decrease power consumption of the mobile station.

Claims

1. A mobile station transfer control system comprising a control apparatus for control over a plurality of cellular mobile communication systems and a mobile station present in a cell under the control of the control apparatus, and constructed in a configuration in which service areas of the respective cellular mobile communication systems regionally overlap each other at least in part,

wherein said control apparatus comprises:

notifying means for notifying said mobile station of cell information indicating whether the mobile station is transferable to a cell while maintaining a current cellular mobile communication system, about each of surrounding cells located around said present cell, and

wherein said mobile station comprises;

a cell information storage for storing the cell information about each surrounding cell notified of by said notifying means;

detecting means for detecting the arrival of transfer timing from the present cell to a surrounding cell;

transfer judging means for, when said detecting means detects the arrival of the transfer timing, judging whether said surrounding cell is a transferable cell to which the mobile station is transferable while maintaining the current cellular mobile communication system, based on the cell information stored in said cell information storage; and

transfer control means for performing such control that when said surrounding cell is said transferable cell, the mobile station transfers to said surrounding cell and that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell of a cellular mobile communication system different from the current cellular mobile communication system.

2. The mobile station transfer control system according to claim 1, wherein said transfer control means performs such control that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell with the highest reception level out of cells of said different cellular mobile communication system.

3. A cell transfer control method in a mobile station transfer control system comprising a control apparatus for control over a plurality of cellular mobile communication systems, and a mobile station present in a cell under the control of the control apparatus, and constructed in a configuration in which service areas of the respective cellular mobile communication systems regionally overlap each other at least in part, the cell transfer control method comprising:

a notification step wherein said control apparatus notifies said mobile station of cell information indicating whether the mobile station is transferable to a cell while maintaining a current cellular mobile communication system, about each of surrounding cells located around said present cell;

a storage step wherein said mobile station stores the cell information about each surrounding cell notified of by said control apparatus, in a cell information storage;

a detection step wherein said mobile station detects the arrival of transfer timing from the present cell to a surrounding cell;

a judgment step wherein when the arrival of the transfer timing is detected, said mobile station judges whether said surrounding cell is a transferable cell to which the mobile station is transferable while maintaining the current cellular mobile communication system, based on the cell information stored in said cell information storage; and

a transfer control step wherein when said surrounding cell is said transferable cell, said mobile station transfers to said surrounding cell and wherein when said surrounding cell is not said transferable cell, the mobile station transfers to a cell of a cellular mobile communication system different from the current cellular mobile communication system.

4. The cell transfer control method according to claim 3, wherein said transfer control step is to perform such control that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell with the highest reception level out of cells of said different cellular mobile communication system.

5. A mobile station comprising:

a cell information storage for storing cell information notified of by a control apparatus for control over a plurality of cellular mobile communication systems service areas of which regionally overlap each other at least in part, said cell information indicating whether the mobile station is transferable to a cell while maintaining a cellular mobile communication system of the control apparatus, about each of surrounding cells;

detecting means for detecting the arrival of transfer timing from a present cell to a surrounding cell;

transfer judging means for, when said detecting means detects the arrival of the transfer timing, judging whether said surrounding cell is a transferable cell to which the mobile station is transferable while maintaining the current cellular mobile communication system, based on the cell information stored in said cell information storage; and

transfer control means for performing such control that when said surrounding cell is said transferable cell, the mobile station transfers to said surrounding cell and that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell of a cellular mobile communication system different from the current cellular mobile communication system.

6. The mobile station according to claim 5, wherein said transfer control means performs such control that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell with the highest reception level out of cells of said different cellular mobile communication system.

7. A cell transfer control method at a mobile station, the cell transfer control method comprising:

a storage step of storing cell information notified of by a control apparatus for control over a plurality of cellular mobile communication systems service areas of which regionally overlap each other at least in part, said cell information indicating whether the mobile station is transferable to a cell while maintaining a cellular mobile communication system of the control apparatus, about each of surrounding cells;

a detection step of detecting the arrival of transfer timing from a present cell to a surrounding cell;

a judgment step of, when the arrival of the transfer timing is detected in said detection step, judging whether said surrounding cell is a transferable cell to which the mobile station is transferable while maintaining the current cellular mobile communication system, based on the stored cell information; and

a transfer control step of performing such control that when said surrounding cell is said transferable cell, the mobile station transfers to said surrounding cell and that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell of a cellular mobile communication system different from the current cellular mobile communication system.

8. The cell transfer control method at the mobile station according to claim 7, wherein said transfer control step is to perform such control that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell with the highest reception level out of cells of said different cellular mobile communication system.

9. A cell transfer control program for making a built-in computer at said mobile station execute each of the steps in the cell transfer control method at the mobile station as set forth in claim 7.

10. A mobile station transfer control system comprising a control apparatus for control over a plurality of cellular mobile communication systems, and a mobile station present in a cell under the control of the control apparatus, said mobile station being classified either as a dedicated mobile station set to be able to utilize only service of one cellular mobile communication system or as a common mobile station set to be able to utilize service of two or more cellular mobile communication systems;

and constructed in a configuration in which service areas of the respective cellular mobile communication systems regionally overlap each other at least in part, the mobile station transfer control system comprising;

control apparatus for performing such control that in a common cell set to be able to offer service to both the dedicated mobile station and the common mobile station, communication resources of a cellular mobile communication system served therein are allocated to each of the dedicated mobile station and the common mobile station and that in an ordinary cell not set as said common cell, communication resources of a cellular mobile communication system served in the ordinary cell are allocated to only the dedicated mobile station of said cellular mobile communication system;

first determining means for, when said mobile station transfers to another cell, determining a transfer target cell as a transfer target of the mobile station within a current cellular mobile communication system in which said mobile station utilizes service thereof;

judging means for judging whether said mobile station is a common mobile station and whether the transfer target cell determined by said first determining means is an ordinary cell; and

second determining means for, when said mobile station is a common mobile station and when the transfer target cell determined by said first determining means is an ordinary cell, determining a common cell of a cellular mobile communication system different from the current cellular mobile communication system, as a new transfer target cell.

11. A control apparatus for allocating communication resources to a mobile station, said mobile station being classified either as a dedicated mobile station set to be able to utilize only service of one cellular mobile communication system out of a plurality of cellular mobile communication systems service areas of which regionally overlap each other at least in part or as a common mobile station set to be able to utilize service of two or more cellular mobile communication systems, the control apparatus comprising:

control means for performing such control that in a common cell set to be able to offer service to both the dedicated mobile station and the common mobile station, communication resources of a cellular mobile communication system served therein are allocated to each of the dedicated mobile station and the common mobile station and that in an ordinary cell not set as said common cell, communication resources of a cellular mobile communication system served in the ordinary cell are allocated to only the dedicated mobile station of said cellular mobile communication system;

first determining means for, when said mobile station transfers to another cell, determining a transfer target cell as a transfer target of the mobile station within a current cellular mobile communication system in which said mobile station utilizes service thereof;

judging means for judging whether said mobile station is a common mobile station and whether the transfer target cell determined by said first determining means is an ordinary cell; and

second determining means for, when said mobile station is a common mobile station and when the transfer target cell determined by said first determining means is an ordinary cell, determining a common cell of a cellular mobile communication system different from the current cellular mobile communication system, as a new transfer target cell.

12. The control apparatus according to claim 11, said control apparatus being comprised of a control section common to at least two cellular mobile communication systems.

13. The control apparatus according to claim 11, said control apparatus being comprised of control sections of the respective cellular mobile communication systems for allocating communication resources of the respective cellular mobile communication systems.

14. An allocating method of communication resources in a mobile station transfer control system comprising a control apparatus for control over a plurality of cellular mobile communication systems, and a mobile station present in a cell under the control of the control apparatus, said mobile station being classified either as a dedicated mobile station set to be able to utilize only service of one cellular mobile communication system or as a common mobile station set to be able to utilize service of two or more cellular mobile communication systems;

and constructed in a configuration in which service areas of the respective cellular mobile communication systems regionally overlap each other at least in part and in which said control apparatus performs such control that in a common cell set to be able to offer service to both the dedicated mobile station and the common mobile station, communication resources of a cellular mobile communication system served therein are allocated to each of the dedicated mobile station and the common mobile station and that in an ordinary cell not set as said common cell, communication resources of a cellular mobile communication system served in said ordinary cell are allocated to only the dedicated mobile station of said cellular mobile communication system, the method comprising;

a transfer request step wherein the mobile station utilizing service of a first cellular mobile communication system sends a request for transfer to another cell, to said control apparatus;

a first determination step wherein said control apparatus determines a transfer target cell as a transfer target of said mobile station within said first cellular mobile communication system;

a judgment step wherein said control apparatus judges whether said mobile station is a common mobile station and whether the transfer target cell determined in said first determination step is an ordinary cell;

a second determination step wherein when said mobile station is a common mobile station and when the transfer target cell determined in said first determination step is an ordinary cell, said control apparatus determines a common cell of a cellular mobile communication system different from said first cellular mobile communication system, as a new transfer target cell; and

a different system resources allocation step wherein said control apparatus allocates communication resources of the cellular mobile communication system of said new transfer target cell to said mobile station.

15. The allocating method of communication resources according to claim 14, further comprising an identical system resources allocation step wherein when said mobile station is not a common mobile station or when the transfer target cell determined in said first determination step is not an ordinary cell, said control apparatus continuously allocates communication resources of said first cellular mobile communication system to the mobile station.

16. A mobile station transfer control system comprising a control apparatus for control over a plurality of cellular mobile communication systems, and a mobile station present in a cell under the control of the control apparatus, said mobile station being classified either as a dedicated mobile station set to be able to utilize only service of one cellular mobile communication system or as a common mobile station set to be able to utilize service of two or more cellular mobile communication systems;

and constructed in a configuration in which service areas of the respective cellular mobile communication systems regionally overlap each other at least in part,

wherein said control apparatus comprises;

notifying means for notifying said mobile station of cell information indicating whether the mobile station is transferable to a cell while maintaining a current cellular mobile communication system, about each of surrounding cells located around said present cell;

control means for performing such control that in a common cell set to be able to offer service to both the dedicated mobile station and the common mobile station, communication resources of a cellular mobile communication system served therein are allocated to each of the dedicated mobile station and the common mobile station and that in an ordinary cell not set as said common cell, communication resources of a cellular mobile communication system served in the ordinary cell are allocated to only the dedicated mobile station of said cellular mobile communication system;

first determining means for, when said mobile station transfers to another cell, determining a transfer target cell as a transfer target of the mobile station within a current cellular mobile communication system in which said mobile station utilizes service thereof;

judging means for judging whether said mobile station is a common mobile station and whether the transfer target cell determined by said first determining means is an ordinary cell; and

second determining means for, when said mobile station is a common mobile station and when the transfer target cell determined by said first determining means is an ordinary cell, determining a common cell of a cellular mobile communication system different from the current cellular mobile communication system, as a new transfer target cell; and

wherein said mobile station comprises;

a cell information storage for storing the cell information about each surrounding cell notified of by said notifying means;

detecting means for detecting the arrival of transfer timing from the present cell to a surrounding cell;

transfer judging means for, when said detecting means detects the arrival of the transfer timing, judging whether said surrounding cell is a transferable cell to which the mobile station is transferable while maintaining the current cellular mobile communication system, based on the cell information stored in said cell information storage; and

transfer control means for performing such control that when said surrounding cell is said transferable cell, the mobile station transfers to said surrounding cell and that when said surrounding cell is not said transferable cell, the mobile station transfers to a cell of a cellular mobile communication system different from the current cellular mobile communication system.