Simplex, half-duplex and full-duplex data transmission


The simplex, duplex and half duplex are three different modes of operations of the network or connection.

Simplex Data Transmission

In simplex transmission data can only transfer in one direction – from transmitter to receiver. It is a “one-way street”. It is not possible to send back data to transmitter. The examples of a simplex transmission are TV, radio and printer.

Half-Duplex Data Transmission

In a half-duplex transmission, the data can transfer in both directions, but not simultaneously. The walkie-talkie (handheld transceiver, or HT) is one of the examples of half-duplex device. It is a two-way radio with a push-to-talk button. When a person wants to speak to other person he pushes this button, which turns on the transmitter but turns off the receiver, so he cannot hear the other person. To listen to the other person he releases the button, which turns on the receiver but turns off the transmitter.

Full-Duplex Data Transmission

In full-duplex transmission data can transfer in both directions simultaneously. There is no need to switch from transmit to receive mode like in half duplex. The data can be sent and received along the same line. The Telephone is an example fo full duplex, as both parties can speak and listen at the same time.

Add new comment