2 - Telecommunication basics

Abstract

This chapter discusses some of the basic telecommunications concepts. It describes different types of channels and their methods of operation. Signaling is one of the most important basic principles in telecommunications because it has to convey information about the call through the telephone system in order to control, route, and maintain the call. In telecommunications, a channel refers to a “logical” transmission path. Using multiplexing techniques such as frequency division multiplexing (FDM), several transmission paths can be created across a single medium and allocated to different users. The quantity of information a channel can convey in a given period is determined by its ability to handle the rate of change of the signal. The chapter also focuses on modulation methods as ways of imposing information on the channel, difference between analog and digital channels, and different ways of making connections across the network. The open systems interconnection (OSI) model introduces the concept of layered architectures and the functions of the various layers are also explained.