In telecommunications, a significant instant is the instant of change from one significant condition to another within a discretely-timed signal [1]
A signal in which the time interval between two successive significant instants is constant is called an isochronous signal. This time interval is called the unit interval.
This article incorporates public domain material from Federal Standard 1037C. General Services Administration. Archived from the original on 2022-01-22. (in support of MIL-STD-188).