Data Components || Data Communication || Bcis Notes

Data Components

The different components of Data communication are described below.

1. Message:
   The message is the information (data) to be communicated. Popular forms of information include text, numbers, pictures, audio, and video.
2. Sender:
   The sender is the device that sends the data message. It can be a computer, workstation, telephone handset, video camera, and so on.
3. Receiver:
   The receiver is the device that receives the message. It can be a computer, workstation, telephone handset, television, and so on.
4. Transmission medium:
   The transmission medium is the physical path by which a message travels from sender to receiver. Some examples of transmission media include twisted-pair wire, coaxial cable, fiber-optic cable, and radio waves.
5. Protocol:
   A protocol is a set of rules that govern data communications. It represents an agreement between the communicating devices. Without a protocol, two devices may be connected but not communicating, just as a person speaking French cannot be understood by a person who speaks only Japanese.

Simplex

In simplex transmission mode, the communication between the sender and receiver occurs in only one direction. The sender can only send the data, and the receiver can only receive the data. The receiver cannot reply to the sender.
Simplex transmission can be thought of as a one-way road in which the traffic travels only in one direction—no vehicle coming from the opposite direction is allowed to drive through.

To take a keyboard/monitor relationship as an example, the keyboard can only send the input to the monitor, and the monitor can only receive the input and display it on the screen. The monitor cannot reply, or send any feedback, to the keyboard.

Half-Duplex

The communication between the sender and receiver occurs in both directions in half-duplex transmission, but only one at a time. The sender and receiver can both send and receive the information, but only one is allowed to send at any given time. Half-duplex is still considered a one-way road, in which a vehicle traveling in the opposite direction of the traffic has to wait till the road is empty before it can pass through. For example, in walkie-talkies, the speakers at both ends can speak, but they have to speak one by one. They cannot speak simultaneously.

Full-Duplex

In full-duplex transmission mode, the communication between the sender and receiver can occur simultaneously. The sender and receiver can both transmit and receive at the same time. The full-duplex transmission mode is like a two-way road, in which traffic can flow in both directions at the same time.

 

You may also like Introduction to Data Communication