IEEE 1588 describes a Precision Time Protocol (PTP) that enables synchronizing distributed clocks to within 1 microsecond via Ethernet networks with relatively low demands on local clocks, the network and computing capacity. There are many applications for example in automation to synchronize elements of a production line (without timing belts).
PTP runs on IP networks, transferring precision time to slave devices via a 1 GHz virtual clock (timebase). Independent masters can be locked to one Grand Master clock, creating wide, or even global locking. SMPTE ST 2059 describes a profile for using PTP IEEE 1588-2 as the synchronising source for media applications. AES67 relies on IEEE 1588-2 to maintain timing with low clock jitter in digital audio systems.
See also: Black and burst, Tri-level sync, PTP, SMPTE ST 2059, Slave Clock, Master Clock