Meaning
Synchronization of clocks across a distributed network to a precision of less than one millionth of a second defines high-accuracy temporal coordination. This sub microsecond synchronization is used in electrical power grids and distributed measurement systems. The capability is necessary for coordinating events that happen at very high speeds across large physical distances.
It prevents data collision and ensures that events are recorded in the correct temporal order.
Protocol Standard
Achieving this level of accuracy often relies on the IEEE 1588 Precision Time Protocol. This protocol uses symmetrical packet exchange to measure and compensate for the propagation delay of the network cables. The protocol divides the network into primary and secondary clocks to maintain a single time reference.
Clock Distribution
System designers must minimize packet delay variation across the network switches to maintain high precision. If a network switch introduces variable delay, the synchronization algorithm cannot calculate the path delay accurately. Dedicated timing networks are often used to isolate synchronization traffic from ordinary data traffic.
Network Hardware
Implementing this level of synchronization requires hardware timestamping capabilities in the network interface cards. Hardware timestamping records the arrival and departure times of synchronization packets at the physical layer, avoiding the variable delays introduced by the operating system software. This hardware support is critical for achieving sub-microsecond precision.
