Synchronization of SDH networks: slave clocks model and stability measures

In SDH-(synchronous digital hierarchy-)based transport networks, the synchronization problem must be carefully considered, in order to guarantee good performance in transporting PDH (plesiasynchronous digital hierarchy) tributaries. In particular, careful design of equipment synchronization strategies is required in order to limit pointer adjustments in SDH streams. A variety of quantities able to characterize clock performance, is presented, and it is shown that the root mean square, relative time interval error is a reliable quantity for characterizing slave clock behavior in ideal operation. An expression for such a quantity is suggested