Computer Networks UNIT - I
DATA COMMUNICATIONS Data communication plays vital role in the world. The word data refers to information presented in whatever form is agreed upon by the parties creating and using the data. Data communications are the exchange of data between two devices via some form of transmission medium such as a wire cable.
Components of a data communication system Sender – sends message to the receiver Receiver – receives messages from the sender Message – data to be transmitted Transmission Medium – used to transmit data Protocol – rules and procedures for data communication
Types of Data flow (simplex, half-duplex, and full-duplex) Simplex : Unidirectional Example: Keyboard to monitor communication Half Duplex : Bidirectional, but not simultaneously Example: Walkie-talkie Full Duplex or duplex : Bidirectional Example: Cell phone