Principles of Synchronous Digital Hierarchy

34 Principles of Synchronous Digital Hierarchy

telephone and a very clear picture on the TV. All the problematic factors can

have their effect only in between the regenerators; the multiplying effects of

impairments at every repeater are simply driven away. As long as the regen-

erator spacing is maintained within acceptable limits for correct reception,

the signal does not deteriorate at all, no matter how many times it is regener-

ated. The concept is illustrated in Figure 2.14.

2.7 Channel Capacity in Digital Technology

In the preceding section the most fundamental advantage of the digital sig-

nal over the analog, i.e., unlimited link lengt