ABSTRACT
This chapter discusses the mathematical analysis of computer clocks, including the effects of environmental factors on oscillator frequency, as well as the modeling of the feedback loop used to discipline time and frequency. In typical computer clocks, the oscillator wander depends largely on ambient temperature variations. In orphan mode, dependent clients are all at the mercy of a single orphan parent clock oscillator. The timescale is produced by an algorithm using periodic measurements of the time offsets between the clocks of the ensemble. Plot the offsets of each clock relative to an arbitrary timescale for many samples. The plot appears as a system of bell-shaped figures slowly processing relative to each other but with some further away from nominal zero than others. The Allan deviation characteristic must be determined for each clock separately since it depends on the prevailing measurement phase noise and clock frequency noise.
