What is Data Transmission?

Transmission: The process of transferring something.

Data Transmission: The communication or transferring of data from one place to another in signals from is called data transmission.

What are the types of Data Transmission?

The transmission of data is categorized into two types. These are:

  1. Asynchronous Data Transmission
  2. Synchronous Data Transmission

Asynchronous Data Transmission

Simple meaning of asynchronous is "not existing at same time"  while asynchronous in the form of data transmission is "the process in which data is transmitted character by character from one computer to another"

Disadvantage: It is not efficient and slow in speed.

Transmission process: Asynchronous Data Transmission use start bits and stop bits. Start bits have 0 value and it is send when a character is about to transmitted. 0 indicate the character is ready to transfer and also alert the receivers to receive data. This state is also called space state. 1 indicates stop bits. Stop bit is send when the character is transfered. After each character a stop bit is send to show that the character is transfered. know how: If 1 occurs in start bits that means the line is idle. This state is called mark state.

Synchronous Data Transmission 

Synchronous is opposite of asynchronous Data Transmission its simple meaning "existing at same time". Synchronous in the form of Data Transmission is "the process in which data is transmitted block by block from computer to another".

Transmission process: It uses clock signals to control data transmission.

Advantages: Synchronous data transmission have lots of advantages over asynchronous Data Transmission. It's is more efficient than asynchronous transmission. It transfer large amount of data as each block consist of many characters. Much faster than asynchronous data transmission because the characters have no gap.

What is difference between Asynchronous and Synchronous data transmission?

Asynchronous Transmission
Synchronous transmission
Transmit data Character by character.

Receiver and sender are  not synchronized each other.

Time interval is not fixed between characters.

Gaps between characters.

Use start and stop bits to Transmit data.

Not more efficient and slow
in data transmission speed.

 Transmit data block by block.

Receiver and sender are synchronized each other.

Time interval is fixed between characters.

There is no Gaps between characters.

Use clock signals that control the  data transmission.

More efficient and fast
in data transmission speed.

Data Transmission Mode

Data is transmitted from one place to another the way in which data is transmitted is known as transmission mode.
Types:
Data transmission modes are of three types:
  1. Simplex Mode
  2. Half-Duplex Mode
  3. Full-Duplex Mode

Simplex Mode

Data can only flow in one direction it's transmission is similar to one-way street. Direction of data flow never change. With Simplex Mode; A device can either send data or receive data cannot perform both at same time. 

Example: Traditional Television

Half-Duplex Mode

In this Mode Data Flow in both directions but not at the same time. With Half-Duplex Mode; A device can only either send data or receive data but not both at same time. Because of this reason it's slow in speed.
Example: Internet Surfing

Full Duplex Mode

In this Mode Data can be transmitted in both directions. Full Duplex Mode is faster as compared to Half-Duplex Mode. It's also save time by not changing direction of data flow.
Example: Telephone.