CONTROL DEVICE AND COMMUNICATION CONTROL METHOD

• US 20090237265A1
• Filed: 02/17/2009
• Published: 09/24/2009
• Est. Priority Date: 03/24/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Eguchi, Tadashi
• Granted Patent: US 8,884,737 B2
• Time in Patent Office: Days
• US Class Current: 340/825
• CPC Class Codes: G08C 17/00 Arrangements for transmitting signals characterised by the use of a wireless electrical link
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

This invention eliminates unnecessary beacon transmission by a DBD and suppresses the power consumption of each device included in a wireless communication network. This invention provides a communication control method in a host which wirelessly communicates with a DBD via a wireless USB. The method includes the steps of transmitting a capture packet command to a DBD when it is activated, analyzing a received captured signal and determining the presence/absence of another Wimedia device unrecognized by the host, and upon determining that the other Wimedia device unrecognized by the host exists, instructing the activated DBD to transmit a beacon to implement wireless communication synchronized with the host.

Claims

1. A control device which communicates with a controlled device, comprising:

a first instruction unit configured to instruct the controlled device to transmit a signal captured by the controlled device to the control device;

a reception unit configured to receive the captured signal transmitted from the controlled device in accordance with the instruction of said first instruction unit;

a decision unit configured to decide, based on the captured signal said reception unit have received from each of a plurality of controlled devices, a controlled device which should transmit a beacon; and

a second instruction unit configured to instruct the controlled device decided by said decision unit to transmit a beacon.

2. The device according to claim 1, wherein said second instruction unit instructs to transmit a beacon to synchronize a communication device as a transmission source of the signal captured by the controlled device with the control device.

3. The device according to claim 1, further comprising a recognition unit configured to recognize, based on the captured signal received by said reception unit, a communication device which exists outside a communication range of the control device but within a communication range of the controlled device which has transmitted the captured signal,

wherein said decision unit decides, based on a recognition result of said recognition unit, the controlled device which should transmit a beacon.

4. The device according to claim 3, further comprising a storage unit configured to store all communication devices which exist within the communication range of the control device,

wherein said decision unit decides, based on a storage result of said storage unit and the recognition result of said recognition unit, the controlled device which should transmit a beacon.

5. The device according to claim 3, wherein if all communication devices recognized by said recognition unit based on a captured signal received from a first controlled device are the same as communication devices recognized based on a captured signal received from a second controlled device, said decision unit decides one of the first controlled device and the second controlled device as the controlled device which should transmit a beacon.

6. The device according to claim 3, wherein if all communication devices recognized by said recognition unit based on a captured signal received from a first controlled device are included in communication devices recognized based on a captured signal received from a second controlled device, and the communication devices recognized based on the captured signal received from the second controlled device includes a communication device different from the communication devices recognized based on the captured signal received from the first controlled device, said decision unit decides the second controlled device as the controlled device which should transmit a beacon.

7. The device according to claim 1, wherein if said decision unit decides, as the controlled device which should transmit a beacon, a controlled device different from a controlled device which has transmitted a beacon so far, said second instruction unit instructs the controlled device which should newly transmit a beacon to transmit a beacon in a beacon slot used by the controlled device which has transmitted a beacon so far.

8. The device according to claim 1, wherein

the control device is a host of a wireless USB,

the controlled device which transmits the captured signal is a directed beaconing device of the wireless USB, and

the communication device which transmits the signal to be captured by the controlled device is a device complying with a Wimedia protocol.

9. A communication control method in a control device which communicates with a controlled device, comprising the steps of:

instructing the controlled device to transmit a signal captured by the controlled device to the control device;

receiving the captured signal transmitted from the controlled device in accordance with the instruction in the instructing step of instructing the controlled device to transmit the signal to the control device;

deciding, based on the captured signal received from each of a plurality of controlled devices in the receiving step, a controlled device which should transmit a beacon; and

instructing the controlled device decided in the deciding step to transmit a beacon.

10. A computer-readable storage medium which stores a control program for causing a computer to execute a communication control method of claim 9.