Time synchronization slave apparatus capable of adjusting time synchronization period, and method of determining time synchronization period

A time synchronization slave apparatus and a method of determining a time synchronization period are disclosed. In the apparatus, a time synchronization processing unit performs a time synchronization operation and determines an offset and a rate used to correct local time error based on a calculated time error, a timer corrects the local time based on the determined offset and rate, a time error estimation unit estimates a time error in the local time during a present time synchronization period, and generates excess error information regarding an excess point at which the estimated time error exceeds a threshold allowable time error range, a time synchronization period determination unit determines a subsequent time synchronization period based on the excess error information, and a synchronization period information transmission unit transmits synchronization period information regarding the subsequent time synchronization period to a time synchronization master apparatus.