Friday 9 March 2012

Week 2 - Data Communication


Assalamualaikum & wassup..

We meet again in my blog.. Well this is my second post. This week we had learnt about DATA COMMUNICATION. Do you know what data communication is??? For me, when I hear the words itself what I had understand from it is the communication that use devices to communicate between at least two person. The devices used in data communication usually the computer and other devices that connect with the internet. First of all, I would like to mentioned about two types of data transmission.


They are:
1)  analog transmission
2)  digital transmission

type of transmission


What is analog transmission?

It's a transmission that uses signal that are exact replicas of a sound wave or image. There are carrier waves whereby the added frequency of electromagnetic current will help to produce a continuous electric wave.

eg: Standard phones, fax machines and modem.

What is digital transmission then?

It is a type of transmission where the signals are converted into a binary digit, which consists of two elements. Where do we usually see digital transmission? Normally, it can be found in the electronic communication.

Next, I would like to talk about bandwidth. BANDWIDTH. I never heard the word before. Bandwidth is the amount of data that can be transferred in a fixed amount of time. There are books that mentioned that bandwidth are defined as the speed of the data transferred. But according to the notes in class, it is about the amount of data, so we stick to that.

The bandwidth are measured by bps (bit per second), Mbps (Megabits per second). It is an advantage to have a higher bandwidth as the data will be transferred faster and efficiently.




Lastly, we will discuss on the directions of data transmission. There are two types:

1) simplex
2) duplex
  - half duplex
  - full duplex

SIMPLEX

It is a one way communication. Data usually travels in single direction. Eg: door bell. However it is very uncommon to be used in computer communication.

HALF DUPLEX

Data can travel in either direction but can only travel in one direction at a time.
eg: USB



That's all for now. I'll see you in my next entry! XD Leave your comment please.. (^_^)


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