What is WiFi? - Computers - Networks

What is WiFi? Many of us are using WiFi technology and most of us for sure do not know real answer on this question. WiFi is abbreviation for wireless fidelity. WiFi are wireless networks which use IEEE 802.11 standards. There is an organization called Wi-Fi Alliance. One of the main tasks of WiFi Alliance is to test equipment of various vendors that are making WiFi equipment like access points, wireless routers and wireless cards. So with label WiFi certified there is an assurance that you are using wireless technology which acts according to the 802.11 standards.On the net and in documentation you could also find widely used name for WiFi networks and technology WLAN. WLAN - Wireless Local Area Network or Wireless LAN is local network which works on WiFi based technology.

When you know the answer on the question - what is WiFi, you could find out how WiFi really works.

WiFi or WLAN works on different frequencies, speeds and using different modulation techniques. This different versions use different IEEE standards for their data transfer:- 802.11a- 802.11b- 802.11g- 802.11n

What is WiFi standard really, and what does it determine?

IEEE 802.11a standard define wireless signals which work on the frequency of 5 GHz. Speed used by 11a standard is 54Mbps and it is almost 5 times greater then speed of 802.11b standard.

IEEE 802.11b standard is working on the frequency of 2.4 GHz and with maximum speed is 11 Mbps. This frequency of 2.4 GHz is unregulated frequency and the providers do not have to pay the license for it. This is a main reason why most of other wireless technologies use this same frequency range. Here is much greater possibility for decreasing the signal strength, because of the interference with other signals. The maximum range in the indoor environment is about 35 meters (117 feet), and in outdoor environment about 100 meters (333 feet).

IEEE 802.11g standard works on the frequency range of 2.4 GHz and its maximum speed is 54Mbps. Because of the same frequency range, hardware which works on this standard is compatible with 802.11b hardware.

What is WiFi 802.11n? Unlike versions of Wireless LAN signals above, 11.n is not standard yet, it is amendment. There is also the difference on the frequencies it is using. 802.11n amendment could run on both frequency bands 2.4 GHz and 5 GHz. But in the most cases you will find equipment labeled as N that uses the frequency of 2.4 GHz. The N WiFi equipment is backward compatible with older standards. This means that if you buy wireless router tagged as 802.11n, it should be compatible with 802.11b and 802.11g, if it is running on frequency of 2.4GHz.

Maximum bandwidth used by 11n is usually 150Mbps, but there are some wireless boxes which could run even on 300 Mbps. The range is 6 times father comparing to 802.11g. As I already mentioned IEEE 802.11n is still not standardized, so all these values of speed and range stated on theses WLAN boxes you should take for granted.

What is WiFi equipment?

As I have already mentioned here, WiFi uses the WLAN standards for a connection between the wireless access points or broadband wireless routers and wireless clients or computers with Wireless internet card.Broadband wireless router is a wireless access point that has routing functionalities and that has broadband connection. Broadband connection is provided by fiber optics, DSL, ethernet or cable modem.Every wireless broadband router is a Wireless access point (connects wireless devices like computers and PDA-s to a wired network) with broadband access and a router (a device that forward packets between computer networks) at the same time. What is WiFi card? It connects devices to the wireless LAN network or the WiFi network. On web you could find the alternative names WiFi card and wireless network card. Wireless network cards supports one or more 802.11a, 802.11b, 802.11g or 802.11n WiFi standards.

access point vs router