Why SDH?

As mentioned in the previous post, the higher the hierarchy of  E/DS signal the multiplexing and demultiplexing techniques became more complex. Adding to it, interworking with two different technologies of E and DS increased the complexity. At the same time, we cannot continue with the same technology with lower rate because the number of people using mobile phone had started to increase in multiple folds.

This demanded a different technology with easier multiplexing and demultiplexing techniques and higher data rates. This resulted in the rise of a new technology standard called SDH (Synchronous Digital Hierarchy).

What's special with SDH?

SDH is amazingly awesome by the way with which lower rate signals are multiplexed in a frame. It is extremely easier to separate them at the receiver side. The data rate has been increased efficiently with this technology. This in turn means that the number of channels in the frame has been increased efficiently without much complexity of separating them.

The multiplexing techniques will be explained in the forthcoming posts.