Transmission Modes

Introduction

In this blog, we will discuss Transmission modes.

Data transmission modes, sometimes also referred to as data communication modes or data directional mode is defined as the direction of the flow of information between two communication devices.

Data transmission modes, sometimes also referred to as data communication modes or data directional mode is defined as the direction of the flow of information between two communication devices.
A bus connecting major components like process, memory, or I/O, called a system bus, helps communicate various devices connected individually.

(See Introduction to Computer Networks)

You can also read about mime protocol.

You can also read about the Layered Architecture in Computer Network.

Types of transmission modes

Now let us look at each one of them in detail.

SIMPLEX MODE

Here, data flows in only one direction. i.e., the flow of data is unidirectional. 

Diagrammatically represented as,

A—>B 

source: Wikipedia

The figure depicts that the sender can only send data, and cannot receive it. Similarly, the receiver can only receive the data but cannot send it.

Examples:

• Sending inputs from mouse or keyboard to CPU. The keyboard can only enter the data, and the CPU can only receive the data from the keyboard.
• Output sent by CPU to monitor.
• Output sent by computer to the printer.
• Radio and TV transmission.

Pros of simplex transmission mode:

• The total capacity of the communication channel can be utilized during the transmission of data. Therefore, more amount of data can be transmitted.
• This is the highest secure data transmission technique.

Cons of simplex transmission mode:

• As communication is unidirectional. So this transmission technique does not support any intercommunication between devices.
• This mode has the lowest performance.

HALF-DUPLEX MODE

Here, data flows in both directions but only in one direction at a time. 

Diagrammatically represented as,

A—>B or B—>A

Source: wikipedia

The figure depicts that when one device is sending, the other can only receive and vice versa. We can say that the entire benefit of the communication channel is utilized in one direction at a time. So in the case of half-duplex mode, it is possible to perform the error detection. If any error occurs, the receiver requests the sender to retransmit the data.

Examples:

• Walkie-talkie.
• Internet Browser. Here at one time, on searching any information, it goes to the server, and at another time, the target information reaches from server to the user.

Pros of half-duplex transmission mode:

• Both systems can send and receive the data. 
• This mode has better performance than the simplex mode.

Cons of half-duplex transmission mode include:

• When one device is sending the data, the other has to wait. This causes a delay in sending the data at the right time.
   

Also see, Message Switching in Computer Networks.

FULL-DUPLEX MODE

Here, data flow in both directions at the same time. 

Diagrammatically represented as,

A—>B and B—>A

Source: wikipedia

The figure depicts that this mode is bi-directional in nature, i.e., data can be sent in both directions simultaneously. We can send as well as receive data. So in full-duplex mode, we have two simplex channels, one channel has traffic moving in one direction and another channel has traffic moving in another direction.

Examples:

• Telephone or Mobile phone. Here two persons can talk and listen at the same time.

Pros of full-duplex transmission mode:

• Both systems can transmit and receive the data at the same time. 
• This mode has the best performance.

Cons of full-duplex transmission mode include:

• If there is no dedication path between the device, then the capacity of the communication channel is divided into two parts. 
  
  You can also read about the network models in computer network and Subnetting in Computer Networks