Introduction to Data communication for UGC NET Computer Science notes

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In this post,let us understand data communication in a simple way.

Introduction:

Before going to learn the data communication,let us know the small story.

Story :

Before the internet, business communicated from country to country or one town to another town through letters.Because of this,it took long time to recieve information.As a result, Business decisions were delayed.

Today we can send information instantly through internet.This make it easy for companies to receive data quickly and make decisions without delay.

This fast exchange of information between the devices is called data communication.

What is data communication?

Data communication means exchange of data between two devices through a transmission medium like cable, wireless etc 

Example: Computer A send data  to Computer B through cable or wifi.

What is needed for Data Communication?

For data communication to happen

Devices must be part of  a communication system.

Hardware-physical devices (like computer,cable,modem etc)

Software- Programs that control communication.

For data communication to be effective,it has four characteristics

Delivery:

Data must reach the correct destination. 

 Example:If you send an email to your friend,it must reach your friend,not someone else.

Accuracy:

Data must arrive without errors.

If data changes during transmission,that is wrong numbers, corrupted message etc.then it is useless.So dat must arrive accurately.

Example:

Sender send data to reciever.Receiver should receive the data accurately what they send the data from sender.

Timeliness:

Data must arrive on time.

Delayed data is useless.

Example:

If your audio sent after 10 seconds delay, conversation impossible.

Jitter:

Data should arrive at equal time interval.

Example:

If video packet are sent every 30 ms

Correct :30ms - 30 ms- 30ms -. Smooth video

Wrong :30 ms - 40 ms -20 ms. - uneven video

Result:

Poor quality

Audio breaking

So data packets must arrive at equal time interval.

For data communication five components are usually mentioned:

Sender

Receiver

Message

Transmission medium

Protocol

Conclusion:

I hope this post helps you to understand data communication in a simple way.if you like this post,like and share this post with your friends and follow my blog for it more updates.