MOBILE TERMINAL, WIRELESS COMMUNICATIONS SYSTEM AND MOBILE TERMINAL CONTROL METHOD

• US 20070189257A1
• Filed: 02/08/2007
• Published: 08/16/2007
• Est. Priority Date: 02/08/2006
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Suzuki, Toshihiro, Kobayashi, Motonari, Takita, Wataru, Khan, Ashiq
• Granted Patent: US 7,848,275 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 52/0219 where the power saving management affects multiple terminals
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile terminal configured to constitute an ad hoc network together with a plurality of other terminals, the mobile terminal includes a packet relay unit configured to execute a relay operation of relaying a packet transferred between the other terminals. A packet transmitter is configured to execute a transmission operation of transmitting a packet generated in the mobile terminal to any one of the other terminals. A power supply manager is configured to execute a power supply control operation. A coordination controller is configured to cause the relay operation and the power supply control operation to be coordinated with each other, and to selectively control whether each of the relay operation, the transmission operation and the power supply control operation is executed.

Claims

1. A mobile terminal configured to constitute an ad hoc network together with a plurality of other terminals, comprising:

a packet relay unit configured to execute a relay operation of relaying a packet transferred between the other terminals;

a packet transmitter configured to execute a transmission operation of transmitting a packet generated in the mobile terminal to any one of the other terminals;

a power supply manager configured to execute a power supply control operation; and

a coordination controller configured to cause the relay operation and the power supply control operation to be coordinated with each other,

wherein the coordination controller selectively controls whether each of the relay operation, the transmission operation and the power supply control operation is executed.

2. The mobile terminal according to claim 1 whereby the coordination controller rejects a packet transmission request from the packet transmitter during a predetermined time period after power-on, and causes only the relay operation to be executed.

3. The mobile terminal according to claim 2, further comprising a determination unit configured to determine the predetermined time period in accordance with any one of an operation time of the packet relay unit, the number of packets relayed by the packet relay unit, a node density in the ad hoc network, and a traffic amount in the ad hoc network.

4. The mobile terminal according to claim 1, wherein the coordination controller rejects a power-off request from the power supply manger and a packet transmission request from the packet transmitter, and causes only the relay operation to be executed during a predetermined time period after completion of the transmission operation.

5. The mobile terminal according to claim 4, further comprising a determination unit configured to determine the predetermined time period in accordance with any one of an operation time of the packet relay unit, the number of packets relayed by the packet relay unit, the node density in the ad hoc network, and the traffic amount in the ad hoc network.

6. The mobile terminal according to claim 1, wherein

the power supply manager detects the amount of remaining power at power-on, and

the coordination controller rejects a packet transmission request from the packet transmitter, and causes only the relay operation to be executed, when the amount of remaining power is less than a fixed amount.

7. The mobile terminal according to claim 1, wherein

the power supply manager detects the amount of remaining power at power-on, and

the coordination controller causes both of the relay operation and the transmission operation not to be executed when the amount of remaining power is less than a fixed amount.

8. The mobile terminal according to claim 1, wherein

the packet relay unit determines whether the mobile terminal holds an active route, and

the coordination controller rejects a power-off request from the power supply manager when the mobile terminal holds the active route.

9. The mobile terminal according to claim 1, wherein

the packet relay unit determines whether the mobile terminal holds an active route, and

the coordination controller issues an instruction to the packet relay unit to execute a power-off advance notice process for prompting the other terminals to switch to another route for the purpose of permitting power-off when the power supply manager requests power-off while the mobile terminal holds the active route.

10. A wireless communication system, comprising:

a plurality of mobile terminals configured to constitute an ad hoc network; and

a core network configured to control the mobile terminals,

wherein each of the mobile terminals comprises;

a packet relay unit configured to execute a relay operation of relaying a packet transferred between the other terminals;

a packet transmitter configured to execute a transmission operation of transmitting a packet generated in the mobile terminal to any one of the other terminals; and

a power supply manager configured to execute a power supply control operation,

wherein the core network causes the relay operation and the power supply control operation to be coordinated with each other, and selectively controls whether each of the relay operation, the transmission operation and the power supply control operation is executed.

11. A mobile terminal control method for controlling a mobile terminal configured to constitute an ad hoc network together with a plurality of other terminals, comprising the steps of:

executing a relay operation of relaying a packet transferred between the other terminals;

executing a transmission operation of transmitting a packet generated in the mobile terminal to any one of the other terminals;

executing a power supply control operation;

causing the relay operation and the power supply control operation to be coordinated with each other; and

controlling whether each of the relay operation, the transmission operation and the power supply control operation is executed.