The acronym “WiFi” stands for “Wireless Fidelity”; it is used to denote a network structure that is based on wireless technology. There are a number of wireless devices and protocol used in today’s ICT world. If you’ve been in a hotel, coffee shop, library or airport lately, likelihoods are you have been somewhere in the centre of a wireless network. A number of individuals also use wireless networking, normally called WiFi or 802.11 networking, to connect their computers at home, office, hotels etc. A number of institutions are trying to use the technology to provide free or low-cost Internet access to residents. In the near future, wireless networking may become so widespread that you can access the Internet just about anywhere at any time, without using cables. WiFi has a lot of advantages; Wireless networks are easy to set up and inexpensive. They’re also inconspicuous unless you’re on the lookout for a place to use your laptop, you may not even notice when you’re in a hotspot. What Is WiFi after all? A wireless network uses radio waves, just like the mobile phones, televisions and radios do. In fact, communication across a wireless network is a lot like two-way radio communication. Here’s what happens; A computer’s wireless adapter translates data into a radio signal and transmits it using an antenna. A wireless router receives the signal and decodes it. The router sends the information to the Internet using a physical, wired Ethernet connection. The process also works in reverse, with the Access point (router) receiving information from the Internet, translating it into a radio signal and sending it to the computer’s wireless adapter. The radios used for WiFi communication are very similar to the radios used for walkie-talkies, mobile phones and other devices. They can transmit and receive radio waves, and they can convert 1s and 0s (bits and bytes) into radio waves and convert the radio waves back into 1s and 0s. WiFi radios have a few notable differences from other radios in that; They transmit at frequencies of 2.4 GHz or 5 GHz. This frequency is considerably higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency allows the signal to carry more data. They use 802.11 networking standards, which come in several flavours; 802.11a transmits at 5 GHz and can move up to 54 megabits of data per second. It also uses orthogonal frequency-division multiplexing (OFDM), a more efficient coding technique that splits that radio signal into several sub-signals before they reach a receiver. This greatly reduces interference. 802.11b is the slowest and least expensive standard. For a while, its cost made it popular, but now it’s becoming less common as faster standards become less expensive. 802.11b transmits in the 2.4 GHz frequency band of the radio spectrum. It can handle up to 11 megabits of data per second, and it uses complementary code keying (CCK) modulation to improve speeds. 802.11g transmits at 2.4 GHz like 802.11b, but it’s a lot faster it can handle up to 54 megabits of data per second. 802.11g is faster because it uses the same OFDM coding as 802.11a. 802.11n is the newest standard that is widely available. This standard significantly improves speed and range. For instance, although 802.11g theoretically moves 54 megabits of data per second, it only achieves real-world speeds of about 24 megabits of data per second because of network congestion. 802.11n, however, reportedly can achieve speeds as high as 140 megabits per second. eddie@afrowebs.com
