Welcome to the world of ‘Information Technology’ if you aren’t already there, that is. In this chapter you will go through the routine procedure of learning about the basic working concept of communications, and also various communication systems.
Unlike the other computer networking books, this book is organized in a bottom-up manner, i.e., it begins at the physical layer and works its way down towards the application layer.The bottom-up approach has several important benefits.
1. It places emphasis on the physical layer, which has been the high"growth area" of hardware and computer networking and communication. Also at top layer, indeed, many of the recent revolutions in computer networking. In preparing the first edition of this book, we believed that the application layer would remain the highest growth area in the field, both in terms of research and actual deployment.
2. Our experience as instructor has been that teaching networking applications near the beginning of the course is a powerful motivational tool. Students are thrilled to learn about how networking applications work- application such as e-mail and the Web which most students use on a daily basis.
3. The bottom-up approach enables instructors to introduce network hardware development at an early stage. Students not only see how popular applications and protocols work, but also learn how easy it is to create their own network applications and application-level protocols.
