Synchronization

Two different time sequences may be synchronized in one sense without being synchronized in another, or synchronized at one time scale whilst being asynchronous in another.

Systems operating with all their parts in synchrony are said to be synchronous.
Some systems may be only approximately synchronized, or plesiochronous.

For some applications relative offsets between events need to be determined, for others only the order of the event is important.
The idea of simultaneity has many difficulties, both in practice and theory.

Some uses of synchronization

• Synchronization of image and sound in sound film.

• Synchronization is important in fields such as digital telephony, video and digital audio where streams of sampled data are manipulated.

• Synchronizers are needed in digital electronic systems such as microprocessors to deal with asynchronous inputs without generating metastable statess.

• Encryption systems usually require some synchronization mechanism to ensure that the receiving cipher is decoding the right bits at the right time.

• Automotive transmissionss contain synchronizers which allow the toothed rotating parts (gears and splined shaft) to be brought to the same rotational velocity before engaging the teeth.

• Synchronization is also important in industrial automation applications.

• Time codes are often used as a means of synchronization in film, video, and audio applications.

• Technologies such as GPS and NTP provide real-time access to a close approximation to the UTC timescale, and are used for many terrestrial synchronization applications.

• Flash photography, see Flash synchronization

• File synchronization

See also

In the field of video and audio engineering:

Order synchronization and related topics:

Compare with: