WiFi Explained
June 7, 2009
WiFi stands for Wireless Fidelity. It is a set of standards for transferring data over a wireless network. Laptops, netbooks and certain mobile phones too can access the internet with WiFi, as long as they have the right equipment. No wires are required. Radio waves are employed for communicating between the devices involved. This works very similar to how the mobile phone signals and TV signals are transmitted. However, the essential difference is that the area of coverage is relatively smaller.
What happens in the background?
There are 2 main parts in a WiFi set-up:-
1. A router that is connected to the internet using an Ethernet cabled connection.
2. The laptop that requires connecting to the internet using WiFi must have a wireless adapter.
Let’s discuss these 2 aspects in detail. The wireless adapter in a laptop or netbook, as well as the router can transmit and receive radio signals. They both also have decoders, which can convert these radio signals into digital format for their understanding. Therefore, when the laptop requires information from the internet, the wireless adapter communicates with the router, using radio signals requesting it to get the desired pages from the internet. The router decodes these radio signals and then through its cabled Ethernet connection, fetches the necessary data, converts it into radio signals and sends it to the wireless adapter of the laptop. This information is decoded again at the laptop end.
WiFi Hotspot
The area around a router, within which WiFi signals can be transmitted and received, is called a WiFi Hotspot. Such hotspots are present in airports, cafes, hotels and other such places.
WiFi Standards
The WiFi standard has been termed as the 802.11 standard by the IEEE (Institute of Electrical and Electronics Engineers). There are 4 main categories of WiFi standards, based on the frequencies they use for data transfer and the speed they offer. They are:-
1. 802.11a – This standard uses the 5GHz frequency for communication. It can achieve high speeds of data transfer – almost 54Mbps.
2. 802.11b – This standard uses lower frequencies for transmission - 2.4GHz. The speed it achieves is also lower – 11Mbps. Initially this standard was most popular as it was least expensive. However, the faster technologies are now becoming cheaper. Hence, the 802.11b standard is losing its popularity.
3. 802.11g – This standard uses the 2.4GHz frequency for communication like the 802.11b standard. But it achieves high speeds of 54Mbps like the 802.11a standard.
4. 802.11n – This is the newest standard of WiFi technology and is still to receive a legal green signal. It is expected to achieve high speeds of data transfers, covering a larger area. It is supposed to boost up speeds of information transfer from 54Mbps to 600Mbps.
The speeds mentioned above are all theoretical. Practically much lesser speeds are achieved. This is due to the fact that there are several factors involved that govern the rate of data transfer between the wireless adapter and the router. For example, if there are too many people connecting to the internet at a particular hotspot, then the access speeds could be much lower than what is normally offered. Moreover, some laptops might even face a disconnecting problem due to the heavy load.
WiFi is currently available in select areas only. Certain places also have many routers located at suitable distances, so that seamless internet connectivity can be obtained across a wider area. With the lightning speed of technology advancement, the future might see internet access without wires anywhere and everywhere.
