WiFi
is the short form for Wireless Fidility.
Wi-Fi is the name for a collection of standards defined by the
Wi-Fi alliance [20]. The standards are defined for use in a local area
network (LAN), commonly used by personal computers. It is based on the
IEEE 802.11 specifications, which is the only specification used for
Wi-Fi for now, although new ones are under development.
A Wireless LAN ( WLAN or
WiFi ) is a data transmission system designed to provide location
independent network access between computing devices by using radio
waves rather than a cable infrastructure. In the corporate enterprise,
wireless LANs are usually implemented as the final link between the
existing wired network and a group of client computers, giving these
users wireless access to the full resources and services of the
corporate network across a building or campus setting.
The widespread acceptance
of WLANs depends on industry standardization to ensure product
compatibility and reliability among the various manufacturers. The
802.11 specification [ IEEE Std 802.11 (ISO/IEC 8802-11: 1999) ]
as a standard for wireless LANS was ratified by the Institute of
Electrical and Electronics Engineers (IEEE) in the year 1997. This
version of 802.11 provides for 1 Mbps and 2 Mbps data rates and a set
of fundamental signaling methods and other services. Like all IEEE 802
standards, the 802.11 standards focus on the bottom two levels the ISO
model, the physical layer and link layer (see figure below). Any LAN
application, network operating system, protocol, including TCP/IP and
Novell NetWare, will run on an 802.11-compliant WLAN as easily as they
run over Ethernet.
