Communication terminal device, information communication system, storage medium, and information communication method

A communication terminal device connected to a network and performing data communications with another communication terminal device through the network, comprising:

• a storage configured to store received information by a self device;
• and
• circuitry configured to:
• judge, based on the received information stored in the storage, whether or not source of the received information is the other communication terminal device;
• monitor, while the self device is operating by a slave unit operation mode and while first master unit in which the self device is registered is operating by a master unit operation mode, whether or not second master unit other than the first master unit exists in the other communication terminal device based on the judgement;
• acquire first judging criterion information used as the criterion which judges the priority as the master unit of the first master unit and second judging criterion information used as the criterion which judges the priority as the master unit of the second master unit;
• and
• decide, when the second master unit is detected by monitoring, based on the first judging criterion information and the second judging criterion information, one of the first master unit and the second master unit as the master unit for the self device, wherein
• the master unit operation mode is the operation mode of the first master unit operating as the master unit, and
• the slave unit operation mode is the operation mode of the communication terminal device operating as a slave unit.

An information communication system comprising a plurality of communication terminal devices connected to a network,

• the communication terminal device comprising:
• a storage configured to store proper information used as a criterion for switching an operation mode between a master unit operation mode and a slave unit operation mode, the proper information includes judging criterion information used as a criterion which judges the priority as a master unit of a self device;
• and
• circuitry configured to:
• judge, based on received information by the self device, whether or not source of the received information is another communication terminal device other than the self device among the plurality of the communication terminal devices;
• monitor whether or not the other communication terminal device is the master unit based on the judgement;
• acquire the judging criterion information of the other communication terminal device detected as the master unit by monitoring;
• and
• switch, while the self device is operating by the master unit operation mode and when the other master unit is detected by monitoring, the master unit operation mode of the self device to the slave unit operation mode based on the judging criterion information of the self device and the judging criterion information of the other master unit acquired, wherein
• the master unit operation mode is the operation mode of the communication terminal device operating as the master unit, and
• the slave unit operation mode is the operation mode of the communication terminal device operating as a slave unit.

A non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a computer including storage and circuitry, cause the computer to perform a method comprising:

• performing data communications with another communication terminal device through a network;
• storing proper information used as a criterion for switching an operation mode between a master unit operation mode and a slave unit operation mode, the proper information includes judging criterion information used as a criterion which judges a priority as a master unit of a self device;
• judging, based on received information by the self device, whether or not source of the received information is the other communication terminal device;
• monitor whether or not the other communication terminal device is the master unit based on the judgement;
• acquire the judging criterion information of the other communication terminal device detected as the master unit by monitoring;
• and
• switch, while the self device is operating by the master unit operation mode and when the other master unit is detected by monitoring, the master unit operation mode of the self device to the slave unit operation mode based on the judging criterion information of the self device and the judging criterion information of the other master unit acquired, wherein
• the master unit operation mode is the operation mode of the communication terminal device operating as the master unit, and
• the slave unit operation mode is the operation mode of the communication terminal device operating as a slave unit.

A non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a computer including storage and circuitry, cause the computer to perform a method comprising:

• performing data communications with another communication terminal device through a network;
• judging, based on the received information stored in the storage, whether or not source of the received information is the other communication terminal device;
• monitoring, while the self device is operating by a slave unit operation mode and while first master unit in which the self device is registered is operating by a master unit operation mode, whether or not second master unit other than the first master unit exists in the other communication terminal device based on the judgement;
• acquiring first judging criterion information used as a criterion which judges a priority as the master unit of the first master unit and second judging criterion information used as a criterion which judges a priority as the master unit of the second master unit;
• and
• deciding, when the second master unit is detected by monitoring, based on the first judging criterion information and the second judging criterion information, one of the first master unit and the second master unit as the master unit for the self device, wherein
• the master unit operation mode is the operation mode of the communication terminal device operating as the master unit, and
• the slave unit operation mode is the operation mode of the communication terminal device operating as a slave unit.

An information communication method for performing data communications between a plurality of communication terminal devices including circuitry, and having a master unit operation mode operating as a master unit and a slave unit operation mode operating as a slave unit, comprising:

• storing, for each of the plurality of communication terminal devices, proper information used as a criterion for switching an operation mode between the master unit operation mode and the slave unit operation mode;
• judging, based on received information by the communication terminal device, whether or not source of the received information is another communication terminal device other than the self device among the plurality of the communication terminal devices;
• monitoring, in the communication terminal device, whether or not the other communication terminal device is the master unit based on the judgement;
• acquiring the judging criterion information of the other communication terminal device detected as the master unit by monitoring;
• and
• switching, while the communication terminal device is operating by the master unit operation mode and when the other master unit is detected by monitoring, the master unit operation mode of the communication terminal device to the slave unit operation mode based on the judging criterion information of the communication terminal device and the judging criterion information of the other communication terminal device detected as the master unit, wherein
• the proper information includes judging criterion information used as a criterion which judges a priority as the master unit of the self device.