Image Number 4 for United States Patent #8060654.
A data communication network may include two or more master clocks, and a synchronization system connected to the master clocks. The synchronization system may determine a time-base for the master clocks. The synchronization system may control the master clocks according to the determined time-base. The data communication network may include one or more slave clocks. The slave clocks may be controlled by a slave clock time-base controller based on time information of a single selected master clock selected from the master clocks.