1.0 INTRODUCTION AND 1.1 OBJECTIVES

 In this unit, we shall learn the basics of Data Communication. Many services and products that we use everyday employ computer networks and data communications in one way or another. Telephone systems, banking systems, cable television, audio and video systems, traffic control systems and wireless telephones are just few examples. This unit shall briefly describe about the data and signal which are the basic units of data transmission. We shall briefly cover about the methods for sending the signal over the different networks i.e., synchronous and asynchronous communication. We shall also discuss about the modem, its functioning and different modes of transmission of data.

1.1 OBJECTIVES

After going through this unit, you should be able to:

  • · define basic constituents of communication system;
  • · understand different types of Signals i.e. digital signal and analog signal;
  • · list types of transmissions;
  • · explain internal working of a modem; and
  • · specify speed of data transmission.

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