TABLE OF CONTENTS The first two chapters have considered the way that a telephone call is set up and how the various networks providing telephone service are interconnected. Also, Chapter 2 introduced the roles of the other types of network: specialised voice networks and data networks. This chapter considers the basic components that go together to make up these networks. In fact these components can be treated as part of a set of building bricks, each of a different shape and size; all of the telecommunications networks described in this book are made up using a suitable mix of these bricks. Subsequent chapters describe the networks and systems in more detail, assuming the reader has an understanding of the basic components described in this chapter.
Any network is a system of nodes and links. There are many examples of networks which are encountered in everyday life. We talk of the road network, where the junctions form the nodes and the stretches of road in between are the links of the network. Similarly, the rail network comprises the rail links joining the station nodes. A further example is that of the airlines network, where airports provide the nodal functions and the airline routes provide the links. Networks can also be on far smaller scale, for example the electrical circuitry in a television set with its physical wires or printed circuit rails linking the nodal electronic components. The various telecommunications networks are similarly made up of a variety of nodal...
