Chapter 1 / 1.3

1.3 A MORE-DETAILED COMMUNICATIONS SYSTEM

Figure 1.1 illustrates the basic functional elements of an electrical communications system, while Figure 1.2 expands this model to show the principal functions performed in a modern digital communications system. Whereas the simple model emphasizes what functions exist, the more-detailed model begins to explain how information is prepared, protected, transmitted, and ultimately reconstructed at the receiver.

Although not all communications systems contain every block shown in Figure 1.2 the model provides a unifying framework for understanding the design of practical systems. Each block performs a specific role in ensuring that information can be conveyed efficiently, reliably, and—where required—securely across an imperfect physical channel.