Saturday 29 June 2013

WiFi

 WI-FI -Wireless Fidelity.

Using Wi-Fi your information will fly in air and reach your computer.
Now-a-days, many people use wireless networking also called as Wi-Fi or 802.11 networking.
It uses radio waves to transfer data and uses two frequency levels either 2.4 GHz or 5 GHz.
HOTSPOTS: Hotspots are simply areas where Wi-Fi can be accessed.

HOW IT WORKS???


To use Wi-Fi connection one's computer should have wireless adapter.
Let us see the working in two ways. One is from client to server and other is from server to client.
CLIENT TO SERVER:
Adapter translates data into radio signals and transmits it to the space using an antenna.
A wireless router receives the signal and decodes it.
The router sends the information to the internet using wired Ethernet connection.
SERVER TO CLIENT:
Router receives information from the internet, translates it to radio signal and transmit it.
Wireless adapter receives the signal and decode it.

VARIOUS STANDARDS OF WIFI:

Its transmission frequency is either 2.4 GHz or 5 GHz, which is higher than frequencies used for mobile phones, television, etc.
Due to high frequency it carries large data.
It has several standards which are explained below:
    802.11a - It transmits data at 5 GHz and move up to 54 megabits of data per second.
          It uses Orthogonal Frequency Division Multiplexing (OFDM), a technique that splits radio signals into sub-signals. This reduces interference.
    802.11b - It transmits data at 2.4 GHz and move up to 11 megabits of data per second.
          It is developed for low cost communication. Also it is slower than the predecessor.
    802.11g - It transmits data at 2.4 GHz and move up to 54 megabits of data per second.
          It is same as 802.11b but speed is somewhat better.
    802.11n - This is the most widely used standard.
          It transmits data at 2.4 GHz and move up to 140 megabits of data per second.
          It can transmit data up to four streams.
    802.11ac - It the newest standard developed recently in 2013.
           It transmits data at 5 GHz and move up to 140 megabits of data per second.
           It is not yet widely used.

No comments:

Post a Comment