If you have accessed Internet from the airport or any other wireless network, you have already used Wi-Fi. This technology has truly 'unplugged' this world and revolutionized Internet usage.
Gone are the days when computers used to be tethered to routers and modems for Internet connectivity. You can sit anywhere you like, with your laptop computer, and access the Internet now; thanks to Wi-Fi technology.
What is Wi-Fi?
Wi-Fi is an abbreviation of Wireless Fidelity. It is the trademark name of standard wireless networking technology. It enables wireless Internet access through radio wave connectivity. This technology is defined by the IEEE 802.11 standard, which was designed to establish uniformity in wireless networking products, produced around the world.
In short, Wi-Fi is synonymous with wireless networking and is made possible through advanced radio communication techniques.
The single most important component of such a network, is a wireless router. It is the connecting link between your laptops, connected in the wireless network and the Internet superhighway. It is a transmitter, as well as receiver of radio signals. It also converts digital signals to analog and analog signals back to digital.
The speed of data transmission on the network, as well as its security, is dependent on the wireless router. The second most important components are wireless adapters fitted in your laptops, that receive and transmit signals to the wireless router.
How Does Wi-Fi Work?
Let's say that you are at your Wi-Fi enabled home and you switch on your laptop for Internet access. Here is how it works for you.
Laptop Wireless Adapter Searches For a Signal
Once you switch on the laptop and its inbuilt or attached wireless adapter is operational, it searches for a network source in the vicinity. The adapter is a transmitter plus receiver of radio signals. It also carries out the functions of a modem, which converts digital signals into analog radio signals and radio signals back to digital.
The wireless router is the gateway for data transmission. These routers communicate over 2.4 GHz and 5 GHz radio frequencies. Higher the frequency, higher is the bandwidth for data transmission.
Wireless Network User Authentication
You will be prompted to provide user authentication to get connected and use the network. Once you log in and enter password, two-way communication between wireless router and adapter can begin.
Data is Transmitted Through Radio Waves
Now, let us understand how data is transmitted over the network. Whenever you open your web browser and request for a web page, the query in the form of a digital signal, is converted by the wireless adapter into a radio carrier signal, through modulation.
This signal is encrypted with either WPA2 or WEP technology, to prevent it from landing in the hands of eavesdroppers. The wireless router decrypts the signal, demodulates it back to a digital signal, sends the query to the ISP, which then routes data back to it.
The web page data, requested by you, is received by the router, encrypted, and modulated to a radio signal in the 2.4 GHz or 5 GHz range. This is received by the adapter, decrypted, and demodulated again to be displayed on your web browser.
All this happens in a very small fraction of a second, as radio waves are a part of the electromagnetic spectrum and travel at the speed of light.
Wi-Fi has liberated us from the bonds and encumbrances of the wired world. The technology that made it possible is two-way radio communication, that has been around for more than a hundred years.