Table of Contents
In this article, you’ll learn about Modes of Transmission in Network such as Simplex, Half Duplex and Full Duplex.
There are three types of communication ,that is possible between the devices.
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.
For example- keyboards and traditional monitors. 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. The half-duplex mode is like a one-lane road with traffic allowed in both directions.
When cars are traveling in one direction, cars going the other way must wait. In a half-duplex transmission, the entire capacity of a channel is taken over by whichever of the two devices is transmitting at the time.
Walkie-talkies and CB (citizens band) radios are both half-duplex systems. The half-duplex mode is used in cases where there is no need for communication in both directions at the same time; the entire capacity of the channel can be utilized for each direction.
3.Full-Duplex
The full-duplex mode is used when communication in both directions is required all the time. The capacity of the channel, however, must be divided between the two directions.
One common example of full-duplex communication is the telephone network. When two people are communicating with a telephone line, both can talk and listen at the same time.
Diagram represent different type of communication between devices.

Comparison Chart between Simplex, Half Duplex and Full Duplex
Basis for Comparison | Simplex | Half Duplex | Full Duplex |
Direction of Communication | Unidirectional | Two-directional, one at a time | Two-directional, simultaneously |
Send / Receive | Sender can only send data | Sender can send and receive data, but one a time | Sender can send and receive data simultaneously |
Performance | Worst performing mode of transmission | Better than Simplex | Best performing mode of transmission |
Example | Keyboard and monitor | Walkie-talkie | Telephone |