Different behaviour of frequency stability measures in independent and synchronized clocks: theoretical analysis and measurement results

The problem of characterizing the synchronization performance plays a central role in the design of SDH based telecommunication networks. Moreover, establishing the suitable quantities for characterizing the frequency stability of timing signals, together with their measurement configurations, is still an open issue in the standardization committees. We deal with some of the most important frequency stability quantities. An analysis envisaging the possibility to theoretically assess such quantities is carried out showing that substantial differences are expected in the behaviour of the above mentioned quantities, depending on the measurement configuration adopted. Besides, a high precision measurement set-up was used to derive experimental results which confirm the main theoretical conclusions and, at the same time, provide a good insight into the behaviour of various stability measures