DCN | Lecture 4 | Transmission Modes in Data Communication System

Communication between two devices can be simplex, half-duplex, or full-duplex.

Types of Transmission Modes

1. Simplex :- In simplex mode, the communication is unidirectional, as on a one-way street. Only one of the two devices on a link can transmit; the other can only receive. Keyboards and traditional monitors are examples of simplex devices. The keyboard can only introduce input; the monitor can only accept output. The simplex mode can use the entire capacity of the channel to send data in one direction.

2. Half-Duplex :- In half-duplex mode, each station can both transmit and receive, but not at the same time.When one device is sending, the other can only receive, and vice versa. Walkie-talkies and CB (citizens band) radios are both half-duplex systems.

3. Full-Duplex :- In full-duplex mode( called duplex), both stations can transmit and receive simultaneously. In full-duplex mode, signals going in one direction share the capacity of the link: with signals going in the other direction. This sharing can occur in two ways: Either the link must contain two physically separate tranmission paths, one for sending and the other for receiving; or the capacity of the channel is divided between signals traveling in both directions. One common example of full-duplex communication is the telephone network.

See Previous Lectures -

DCN | Lecture 1 | Data Communication and its System Components

DCN | Lecture 2 | Basic Block Diagram of Data Communication System

DCN | Lecture 3 | Effectiveness of Data Communication System