Waiting Time Jitter

When a number of lower speed digital signals are to be time division multiplexed to form a higher speed signal, it is necessary that the lower speed signals all be synchronous. If the sources of these signals are remote, this synchronization will be difficult to achieve. One way of achieving it is to distribute timing information from a master clock to the local clocks at the sources of the lower speed digital signals. In many situations, however, using a master clock and synchronizing the entire digital communication network is either not possible or not economically desirable. An alternative method of achieving synchronization is to use pulse stuffing synchronization. 1 " The pulse stuffing synchronization scheme is reviewed in the next section. Basically, the idea is to bring the symbol rates of each of the incoming lines up to some common rate just before multiplexing by inserting dummy pulses. After demultiplexing, the dummy pulses are removed and each of the signals retimed to smooth out the gaps. 165