How Does Wireless Networking Work?
If you've been in a coffee shop, library, hotel or airport recently, chances are you've been right in the center of a wireless network. A lot of people also use wireless networking, also known as WiFi or 802.11 networking, to connect their computers at home, and some cities are seeking to use the technology to supply free or inexpensive Internet access to residents. In the near future, wireless networking may become so distributed that you will be able to access the Internet just about anywhere at any time, without using wires. WiFi has many advantages. Wireless networks are simple to set up and affordable. They're also unnoticeable -- unless you are on the lookout for a spot to use your laptop, you may not even notice when you're in a hotspot.
A wireless network begins with the sending and receiving of data. Any information that your computer means to share over a network is first sent to the network's wireless adapter. This information can be anything from sending and receiving extensive files to simple text instant messages from one computer to another. The adapter translates this data into a radio signal, which it then transmits over an antenna either directly to another computer or to a router.
The other computer (thru another wireless adapter) or the router picks up the radio signal and changes it back into a format that computers can translate. Once this has occurred, the information can be accessed by all computers on the network if they have been given access, or only to individual computers if the specification was made. This whole operation can pass quickly for small files, or can require some time dependant on file size and speed of antennas and routers.
Connecting to the Internet works in practically the same manner as the sharing of information over a network. The wireless router or antenna (depending once more on the number of computers connected to the network) receives information from the various Internet Service Providers thru a modem in the form of a radio signal. The wireless adapter or modem then permits the computers connected to them to use this information in any way they desire.
You may be curious as to why people refer to WiFi as 802.11 networking. The 802.11 designation comes from the IEEE - the Institute of Electrical and Electronics Engineers. The IEEE sets standards for a range of technical protocols, and it uses a numbering system to classify these standards. The radios used for WiFi communication are very similar to the radios used for walkie-talkies, cell phones and other devices. They can send and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. But WiFi radios have some notable differences from other radios:
WiFi radios send at frequencies of 2.4 GHz or 5 GHz. This frequency is substantially higher than the frequencies used for cell phones, walkie-talkies and televisions. The higher frequency permits the signal to transmit more information. They use 802.11 networking standards, which come in numerous flavors: 802.11a transmits at 5 GHz and can propel up to 54 megabits of data per second. It also uses orthogonal frequency-division multiplexing (OFDM), a more effective coding method that divides that radio signal into numerous sub-signals before they reach a receiver. This greatly cuts down interference.
802.11n is the latest standard that is widely available. This standard significantly improves speed and range. For example, although 802.11g in theory moves 54 megabits of data per second, it only reaches real-world speeds of about 24 megabits of data per second because of network congestion. 802.11n, however, reportedly can attain speeds as high as 140 megabits per second. The standard is presently in draft form --(IEEE) plans to officially ratify 802.11n by the end of 2009.