Patent ID: 8689035

Claim:
A communication system comprising: a first interface board and a second interface board that send and receive data respectively, the first interface board including: a first synchronizer that synchronizes a first time that is the time of the first interface board to a base time based on a master synchronization signal that is supplied by an external master time source and that defines the base time, a first comparator that compares a phase of a first synchronization signal that synchronizes the first time, with a phase of a shared synchronization signal, and a first notifier that notifies the second interface board of a comparison result of the first comparator, the second interface board including a second synchronizer that synchronizes a second time that is the time of the second interface board to the base time based on the comparison result notified from the first notifier; and an interface controller that controls the first and second interface boards respectively, the interface controller including a transmitter that sends the shared synchronization signal inside the communication system to the first and second interface boards.