Preview and Introduction

Abstract

From the age of primitive science, when definition of science was not known as ‘special knowledge’, communication is essential. When animals felt the urge of expressing something to their neighbor, they started communicating. Human is also a social animal. A man alone is nothing but a small island surrounded by a large ocean. By virtue of the intellect, human being must have much stronger expressions and feelings of mind than that of the other animals. In the present chapter, process of communication is described briefly in respect of distance between the communicating nodes or subjects, and also in respect of direction of communication. By which physical quantity we communicate information is discussed then and called a signal. Next, long distance communication, i.e. telecommunication is broadly divided with respect of signal used for communication as analog and digital communication. At the rear end of the chapter, the important elements of digital communication are depicted using blocks.