File transmission/reception device and control method of file transmission/reception device

1. A control method of a file transmission/reception device, the method comprising:

if in near field communication a conflict occurs in a connection at a second communication layer higher than a first communication layer with an opposing device, cutting off the connection at the second communication layer with the opposing device;

determining a mode of the file transmission/reception device when performing a re-connection at the second communication layer via the connection at the first communication layer with the opposing device as any one mode of a master mode and a slave mode;

switching the file transmission/reception device to the decided mode; and

performing transmission, reception, or transmission/reception of a file with the opposing device and the file transmission/reception device in the decided mode;

wherein the determining includes:

checking whether the opposing device is compliant with a bidirectional communication operation,

if the opposing device is compliant with the bidirectional communication operation, deciding the mode such that the file transmission/reception device performs a bidirectional communication process,

if the opposing device is not compliant with the bidirectional communication operation, deciding the mode such that the file transmission/reception device performs a unidirectional communication process.

2. The method according to claim 1 , wherein

the checking includes checking whether the opposing device is compliant with the bidirectional communication operation, based on specification information of the opposing device acquired via the connection at the first communication layer from the opposing device after occurrence of the conflict.

3. The method according to claim 1 , further comprising

if the opposing device is compliant with the bidirectional communication operation, acquiring identification information used for identifying the opposing device via the connection at the first communication layer from the opposing device after occurrence of the conflict, before the cutting,

wherein the deciding the mode such that the file transmission/reception device performs a bidirectional communication process includes deciding the mode of the file transmission/reception device when performing the re-connection based on a result of a comparison between the identification information of the opposing device and identification information of the file transmission/reception device.

4. The method according to claim 1 , wherein

the switching includes, if the opposing device is compliant with the bidirectional communication operation, after the cut-off of the connection at the second communication layer with the opposing device, switching the mode of the file transmission/reception device when performing the re-connection to the slave mode and, in a case that a connection request is not received from the opposing device, switching to the master mode the mode of the file transmission/reception device after a predetermined time has elapsed.

5. The method according to claim 1 , further comprising:

acquiring identification information used for identifying the opposing device via the connection at the first communication layer from the opposing device after occurrence of the conflict before the cutting;

acquiring again the identification information via the connection at the first communication layer from the opposing device in a process of performing the re-connection at the second communication layer; and

notifying connection establishment in a case where the acquired identification information matches the identification information of the file transmission/reception device.

6. The method according to claim 1 , wherein

the switching includes, if the opposing device is compliant with the bidirectional communication operation, after completing a process of one mode of the master mode and the slave mode, performing control of switching to the other mode.

7. The method according to claim 6 , wherein

the switching includes, if the opposing device is compliant with the bidirectional communication operation and the file transmission/reception device is in the master mode, performing control of cutting off the connection at the second communication layer with the opposing device after completing the process of master mode.

8. The method according to claim 1 , wherein,

the switching includes, if the opposing device is not compliant with the bidirectional communication operation, switching to the slave mode the mode of the file transmission/reception device when performing the re-connection.

9. The method according to claim 1 , wherein,

the switching includes, if the opposing device is not compliant with the bidirectional communication operation, switching to the slave mode the mode of the file transmission/reception device when performing the reconnection at the second communication layer.

10. The method according to claim 1 , further comprising

performing control of transmitting or receiving only a file satisfying a condition set based on transmission condition information acquired from the opposing device.

11. The method according to claim 10 , wherein,

in a case that the opposing device is connected to a plurality of host devices, the transmission condition information is set as identification information used for identifying each of the host devices.

12. The method according to claim 1 , wherein,

the near field communication is TransferJet.

13. The method according to claim 1 , further comprising:

generating a transmission history list including identification information of the opposing device and information of transmitted files and received files; and

setting files that have not been transmitted to the opposing device as transmission target files based on a result of a comparison between the transmission history list, which is generated by the opposing device, acquired via the connection at the first communication layer from the opposing device and a transmission history list of the file transmission/reception device.

14. The method according to claim 1 , further comprising:

generating a transmission history list including identification information of the opposing device and information of transmitted files and received files; and

requesting the opposing device to transmit files that have not been received by the file transmission/reception device based on a result of a comparison between a transmission history list, which is generated by the opposing device, acquired via the connection at the first communication layer from the opposing device and the transmission history list of the file transmission/reception device.

15. The method according to claim 13 , further comprising:

storing in a packet storing unit packets configuring a file acquired via the connection at the first communication layer from the opposing device through a plurality of times of file reception;

restoring the file from the packets stored in the packet storing unit; and

recording, in the transmission history list, information of packets that have been successfully transmitted or received among the packets configuring the file in the transmission history list.

16. The method according to claim 13 , further comprising:

after the connection establishment with the opposing device, acquiring the transmission history list, which is generated by the opposing device, via the connection at the first communication layer from the opposing device.

17. The method according to claim 13 , in a case that the file transmission/reception device is connectable to a host device, further comprising:

storing, in a register unit that is usable for the host device, information of a file size of a file that is in the middle of transmission or reception and a file size of a file of which transmission or reception has been completed.