Information terminal device, radio communication system and radio communication method

• US 20070265009A1
• Filed: 05/08/2007
• Published: 11/15/2007
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Hamaguchi, Takayuki
• Granted Patent: US 7,787,821 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04M 1/72412 using two-way short-range wireless interfaces
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• 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: Y02D 30/70 in wireless communication networks

Abstract

An information terminal device (terminal) has a first radio communication unit capable of performing radio communication with low power consumption and a second radio communication unit performing data communication using a wireless LAN. In an ad-hoc mode in which data communication is performed between the terminals, as a rule, the second radio communication unit is set in a sleep mode. However, when actual data communication is necessary, an activation signal is transmitted to a terminal as a communication party by using the first radio communication unit to activate the second radio communication unit. After completion of data communication, a stop signal is transmitted to the terminal as the communication party by using the first radio communication unit to stop the second radio communication unit on the transmission side. In such a manner, transmission of a beacon signal from the second radio communication unit is suppressed, and proper power saving is realized.

Claims

1. An information terminal device having a display, comprising:

(a) a data communication unit capable of switching between an active state and an inactive state and performing radio data communication with another information terminal device;

(b) a low-power communication unit capable of performing radio communication with said another information terminal device with power consumption smaller than that of said data communication unit; and

(c) a controller which sets said data communication unit to said inactive state except for a communication process period in which process necessary for said data communication is performed, start timing and/or end timing of said communication process period being able to be obtained by said low-power communication unit.

2. The information terminal device according to claim 1, wherein in the case where a predetermined radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, said controller determines that it is said start timing of said communication process period and sets said data communication unit to said active state.

3. The information terminal device according to claim 1, further comprising:

(d) a signal relay unit which, when a predetermined radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, transmits a radio signal corresponding to said predetermined radio signal from said low-power communication unit to an other information terminal device.

4. The information terminal device according to claim 1, wherein in the case where a specific radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, said controller determines that it is said end timing of said communication process period and sets said data communication unit to said inactive state.

5. The information terminal device according to claim 1, further comprising:

(e) an operation unit for accepting a predetermined operation; and

(f) a unit for setting at least said data communication unit to said active state in response to said predetermined operation.

6. The information terminal device according to claim 1, wherein said low-power communication unit has a short-range radio device whose communicatable range is narrower than that of said data communication unit.

7. The information terminal device according to claim 1, wherein said data communication unit has a wireless LAN device capable of performing radio communication at speed higher than said low-power communication unit.

8. The information terminal device according to claim 1, wherein said display is a display device having a memory characteristic.

9. The information terminal device according to claim 1, wherein said low-power communication unit is used only for an operation of obtaining a timing related to said communication process period.

10. A radio communication system capable of forming a radio network among a plurality of information terminal devices each having a display, each of said plurality of information terminal devices comprising:

a data communication unit capable of switching between an active state and an inactive state and performing radio data communication with another information terminal device;

a low-power communication unit capable of performing radio communication with said another information terminal device with power consumption smaller than that of said data communication unit; and

a controller which sets said data communication unit to said inactive state except for a communication process period in which process necessary for said data communication is performed, start timing and/or end timing of said communication process period being able to be obtained by said low-power communication unit.

11. The radio communication system according to claim 10, wherein said plurality of information terminal devices include a first information terminal device, a second information terminal device, and a third information terminal device positioned between said first information terminal device and said second information terminal device, and

said third information terminal device has a signal relay unit which, when a predetermined radio signal transmitted from said low-power communication unit of said first information terminal device is received by said low-power communication unit, transmits a radio signal corresponding to said predetermined radio signal from said low-power communication unit to said second information terminal device.

12. The radio communication system according to claim 10, wherein said low-power communication unit is used only for an operation of obtaining a timing related to said communication process period.

13. A radio communication method using an information terminal device having a display, comprising the steps of:

(a) performing radio data communication with another information terminal device by a data communication unit of said information terminal device capable of switching between an active state and an inactive state;

(b) performing radio communication with said another information terminal device by a low-power communication unit of said information terminal device capable of performing radio communication with power consumption smaller than that of said data communication unit; and

(c) performing a control for setting said data communication unit to said inactive state except for a communication process period in which process necessary for said data communication is performed, start timing and/or end timing of said communication process period being able to be obtained in the step (b).

14. The radio communication method according to claim 13, wherein in said step (c), in the case where a predetermined radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, it is determined as said start timing of said communication process period, and said data communication unit is set to said active state.

15. The radio communication method according to claim 13, further comprising the step of:

(d) in the case where a predetermined radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, transmitting a radio signal corresponding to said predetermined radio signal from said low-power communication unit to an other information terminal device.

16. The radio communication method according to claim 13, wherein in the step (c), in the case where a specific radio signal transmitted from said low-power communication unit of said another information terminal device is received by said low-power communication unit, it is determined as said end timing of said communication process period, and said data communication unit is set to said inactive state.