Root mean square time interval error accumulation along slave clock chains

The main aspects of synchronization strategies suitable for application to synchronous digital hierarchy (SDH) based transport networks are discussed, with particular emphasis on the relative phase stability of distributed timing signals. Based on a mathematical model of slave clocks and a reference structure of the synchronization network, a theoretical approach to the calculation of root mean square relative time interval error between SDH equipment clocks and the primary reference clock of the network is described. The comparison of results from extensive calculations allows more insight on the behavior of cascaded slave clocks and the derivation of important suggestions for the synchronization network design