Difference between Simplex, Half duplex and Full Duplex Transmission Modes

In communication systems, the data transfer between a sender and a receiver follows a particular mode which is also known as the "transmission mode". On the basis of the nature of data sent and received, we can categorize the Transmission modes as Simplex, Half−duplex, and Full−duplex.

Read this article to find out more about these transmission modes and what sets them apart.

Simplex Mode of Data Transmission

In a data communication network, when there is a single movement of data or one control movement of data from the sender to the receiver, then it is called the Simplex mode of transmission. In other words, when the data flow is allowed only in one direction, i.e., from sender to receiver only, it is called as simplex mode of data transmission. This means that the receiver cannot send a response back to the sender.

Simplex mode is commonly used for broadcast communications, such as radio and television, where the sender broadcasts information to multiple receivers but does not receive any feedback.

Half-Duplex Mode of Data Transmission

Half duplex mode is a type of transmission in which data can be transmitted in both directions, but not at the same time. When data or signal can be transferred in both sides (from sender to receiver and from receiver to the sender as well), but in one direction at a time, it is known as half duplex mode of data transmission.

Half duplex mode is commonly used for communication between two devices over a single channel, such as a walkie−talkie or a two−way radio.

Full-Duplex Mode of Data Transmission

In a data communication network, when the data can flow over the network in both directions, i.e. from sender to receiver and vice−versa, simultaneously, then it is known as full−duplex mode of data transmission. This means that the sender and receiver can both transmit and receive data at the same time.

A common example of full−duplex mode is a telephone, where two persons can speak and listen simultaneously.

Difference between Simplex, Half duplex and Full Duplex Transmission Modes

Following are the important differences among Simplex, Half duplex and Full Duplex Transmission Modes −

Key	Simplex Mode	Half Duplex Mode	Full Duplex Mode
Definition	Simplex Mode is the mode of transmission in which there is only unidirectional flow of data i.e., participant does only one task which means sender can only send the data and can't receive.	Half duplex is the mode of transmission in which there is bi−directional flow of data but one at a time, i.e., Sender can send as well as receive the data but does one task at a time.	Full Duplex is the mode of transmission in which again there is bi−directional flow of data, i.e., Sender can send as well as receive the data at the same time.
Data flow	Data flow in case of Simplex Mode is Unidirectional.	Data flow is two−directional but one at a time.	Data flow is twodirectional and is simultaneous.
Performance	Simplex Mode of transmission is treated as worst performing mode of transmission as it takes longest time in data transmission.	The performance of Half−duplex is better as compared to Simplex but is lower as compared to Full−Duplex mode of transmission.	Full−Duplex has best performance as compared to that of Simplex and Half−Duplex mode of transmission.
Example	Examples of Simplex mode of transmission are keyboard and monitor.	Walkie−Talkies operate in halfduplex mode	The mode of transmission in telephones is fullduplex.

Conclusion

From the above comparison, it is clear that the basis of this classification of transmission modes is the flow of data over a network. In the simplex mode, the data flow is unidirectional. In the half−duplex mode, data can flow in both directions, but in one direction at a time. In the full−duplex mode, data can flow in both directions simultaneously.

In general, the choice of transmission mode depends on the type of communication and the available resources. Simplex mode is useful for simple, one−way communication, while half duplex and full duplex modes are better suited for more complex, two−way communication