COMMUNICATION APPARATUS, CONTROL METHOD FOR COMMUNICATION APPARATUS, AND COMMUNICATION SYSTEM

• US 20090240781A1
• Filed: 11/24/2006
• Published: 09/24/2009
• Est. Priority Date: 11/28/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Otsuka, Mitsuru
• Granted Patent: US 8,706,829 B2
• Time in Patent Office: Days
• US Class Current: 709/208
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

In a system that performs communication between master and slave, the device better suited as the master device is not always the master device, since the device that initially constructs the network becomes the master device. A device that enters the network later transmits a restart request on detecting the master device, and if a restart permission is received, the device transfers to a restart state and transmits a master inquiry before the device that was the master device up until that point. Thus, a device that newly enters a network is able to operate as the master device even if a master device already exists in the network.

Claims

1. A communication apparatus that operates in a network as one of a master device and a slave device, comprising:

a requesting unit that makes a network reconstruction request to another communication apparatus;

a determination unit that determines whether the communication apparatus is to newly become the master device or the slave device based on the response to the request by the requesting unit; and

a setting unit that sets a standby time until start of an operation for deciding on a new master device, based on the determination by the determination unit.

2. The communication apparatus according to claim 1, wherein the setting unit sets the standby time until search is next made for a master device.

4. The communication apparatus according to claim 1, further comprising:

a detection unit that detects the master device, wherein

the requesting unit makes the network reconstruction request to the master device detected by the detection unit.

5. The communication apparatus according to claim 1, further comprising:

an acquisition unit that acquires a device capability of the other communication apparatus; and

a decision unit that decides whether to exchange the master device and the slave device, based on the device capability acquired by the acquisition unit, wherein

the requesting unit makes the network reconstruction request according to the decision by the decision unit.

6. The communication apparatus according to claim 1, further comprising:

an acquisition unit that acquires a device capability of the other communication apparatus; and

a detection unit that detects a user instruction as to whether to exchange the master device and the slave device, wherein

the requesting unit makes the network reconstruction request according to the result of the detection by the detection unit.

7. The communication apparatus according to claim 1, further comprising:

a notifying unit that notifies a device capability of the communication apparatus to the other communication apparatus; and

a master designation reception unit that receives a master device designation, wherein

the requesting unit makes the network reconstruction request according to the result of the reception by the master designation reception unit.

8. The communication apparatus according to claim 1, wherein

the setting unit sets the standby time to a smaller value than a standby time of the other communication apparatus, if network reconstruction permission is received as the response to the network reconstruction request by the requesting unit.

10. The communication apparatus according to claim 8 further comprising:

a transmission unit that transmits a response to the network reconstruction request received by the reception unit, wherein

the setting unit sets the standby time to a larger value than the standby time of a communication apparatus to which network reconstruction permission is transmitted by the transmission unit.

11. The communication apparatus according to claim 8, further comprising:

an acquisition unit that acquires a device capability of another communication apparatus;

a decision unit that decides whether to exchange the master device and the slave device, based on the device capability acquired by the acquisition unit; and

a notifying unit that notifies a master device designation to a communication apparatus that is next to become the master device, according to the result of the decision by the decision unit.

14. The communication apparatus according to claim 8, wherein the setting unit sets the standby time until search is next made for a master device.

16. A computer-readable storage medium on which is stored a computer program for making a computer function as a communication apparatus of claim 1.

17. A computer-readable storage medium on which is stored a computer program for making a computer function as a communication apparatus of claim 8.

3. (canceled)

9. A communication apparatus that operates in a network as one of a master device and a slave device, comprising:

a reception unit that receives a network reconstruction request;

a determination unit that determines whether the communication apparatus is to newly become the master device or the slave device, based on result of the reception by the reception unit; and

a setting unit that sets a standby time until start of an operation for deciding on a new master device, based on the determination by the determination unit.

12. A control method for a communication apparatus, comprising:

a requesting step of making a network reconstruction request to another communication apparatus;

a determination step of determining whether the communication apparatus is to newly become the master device or the slave device based on the response to the request in the requesting step; and

a setting step of setting a standby time until start of an operation for deciding on a new master device, based on the result of the determination in the determination step.

13. A communication system composed of communication apparatuses that operate as a master device or a slave device,

the slave device comprising:

a requesting unit that makes a network reconstruction request to the master device; and

a setting unit that sets a standby time until the start of an operation for deciding on a new master device, based on the response to the request, and

the master device comprising;

a reception unit that receives the network reconstruction request; and

a setting unit that sets a standby time until the start of an operation for deciding on a new master device, based on the result of the reception by the reception unit.

15. A control method for a communication apparatus, comprising:

a reception step of receiving a network reconstruction request;

a determination step of determining whether the communication apparatus is to newly become the master device or the slave device, based on result of the reception in the reception step; and

a setting step of setting a standby time until start of an operation for deciding on a new master device, based on the result of the determination in the determination step.