Explain the basic architecture of digital switching systems.

An easy N X N time division space switch is demonstrated in figure. The switch can be shown in an equivalence form as a two-stage network along with N X 1 and 1 X N switching matrices for the first and second stages correspondingly as demonstrated in figure. The network has one connection interconnecting the two stages. All inlet/outlet is a single speech circuit consequent to a subscriber line. The speech is carried like PAM analogue samples or PCM digital samples, occurring at 125-µ s intervals. When PAM samples are switched in a time division manner, the switching is termed as analogue time division switching. When PCM binary samples switched, then the switching is termed as digital time division switching. In figure, the interconnected by an appropriate control mechanism and the speech sample transferred by the inlet to the outlet.

FIG - Two - stage Equivalence