Time synchronization subdevice, time sharing system, time sharing method, and recording medium

A time sharing method to be implemented by a time synchronization subdevice for sharing shared time with a time synchronization reference device and relaying distribution of the shared time to another time synchronization subdevice, the time synchronization reference device being a time synchronization reference node to distribute the shared time, the time sharing method comprising:

• receiving periodic data transmitted periodically from the time synchronization reference device;
• transmitting, when the received periodic data is interrupted, first priority information to be transmitted with the periodic data being continuously received to the another time synchronization subdevice, the first priority information indicating a first priority assigned to the time synchronization reference device, the first priority indicating a degree of priority in selecting the time synchronization reference node;
• distributing, when the periodic data is interrupted and a second priority assigned to the time synchronization subdevice is higher than a second priority assigned to a device different from the time synchronization subdevice, time measured by clocking circuitry different from the time synchronization reference device as new shared time to the another time synchronization subdevice;
• and
• stopping transmission of the first priority information when the second priority assigned to the time synchronization subdevice is lower than the second priority assigned to the other device.

A non-transitory computer-readable recording medium storing a program to be executed by a time synchronization subdevice for sharing shared time with a time synchronization reference device and relaying distribution of the shared time to another time synchronization subdevice, the time synchronization reference device being a time synchronization reference node to distribute the shared time, the program causing the time synchronization subdevice to perform operations comprising:

• receiving periodic data transmitted periodically from the time synchronization reference device;
• transmitting, when the received periodic data is interrupted, first priority information to be transmitted with the periodic data being continuously received to the another time synchronization subdevice, the first priority information indicating a first priority assigned to the time synchronization reference device, the first priority indicating a degree of priority in selecting the time synchronization reference node;
• distributing, when the periodic data is interrupted and a second priority assigned to the time synchronization subdevice is higher than a second priority assigned to a device different from the time synchronization subdevice, time measured by clocking circuitry different from the time synchronization reference device as new shared time to the another time synchronization subdevice;
• and
• stopping transmission of the first priority information when the second priority assigned to the time synchronization subdevice is lower than the second priority assigned to the other device.