Summary

This chapter has presented the statistical measures of Timing Deviation (TDEV) and Maximum Time Interval Error (MTIE) as meaningful tools in characterising clock performance. The inapplicability of conventional variance and standard deviation has been discussed. The rationale behind TDEV has been presented as well as its definition in various forms. A useful approximation to TDEV has been presented and utilised in order to show the filtering characteristic inherent in TDEV. The use of TDEV in characterising noise types has also been shown. The following chapter draws on the theory presented in chapters 3 and 2 in order to show the equivalence between the ETSI model and noise sources typical in phaselock loops and proposes an extension.