Jitter Definition

To be unsteady with many small, rapid movements.

To be nervous; have the jitters; fidget.

An unsteady condition in which there are many small, rapid movements.

A jittering movement; a tic.

A fit of nervousness. Often used with the.

Uneven fluctuations in a video or audio signal, causing distortion.

An unwanted variation in the arrival times of a sequence of data packets over a digital network.

Uncertain variation in the timing of a received signal as compared to the timing of the transmitted signal. All signals experience some amount of delay, or latency, as they propagate across a circuit as, even at the speed of light, it takes some amount of time to travel the distance from one point to another. The timing of the signal elements remains consistent, however, barring changes in the length or other physical characteristics of the circuit caused by variations in temperature or other external forces. As devices are added to a circuit, even relatively simple devices such as amplifiers and repeaters performing relatively simple processes, additional delay is introduced, and the potential for variability in delay is increased because of factors such as fluctuations in power sources and faulty internal components. Should variability exceed specified tolerances, the timing of the pulses can be unacceptably irregular, and the receiving device may be unable to interpret the received signal correctly.

Variability in latency of a block, cell, frame, packet, or other message unit. Data message units can suffer jitter not only due to issues of signal jitter, but also because they may encounter different levels of congestion, which may cause them to spend different amounts of time in queues.These factors, and others, contribute to jitter. Some applications, such as e-mail, are tolerant of jitter, while other applications, such as real-time, uncompressed voice, are highly intolerant of jitter.