A wireless local area network (WLAN) links
two or more devices using some wireless
distribution method (typically spread-
spectrum or OFDM radio), and usually
providing a connection through an access
point to the wider internet.
This gives users the mobility to move around
within a local coverage area and still be
connected to the network.
Most modern WLANs are based on IEEE
802.11 standards, marketed under the Wi-Fi
Norman Abramson, a professor at the University of
Hawaii, developed the world’s first wireless computer
In 1979, F.R. Gfeller and U. Bapst published a paper in the
IEEE Proceedings reporting an experimental wireless local
area network using diffused infrared communications.
The first generation of wireless data modems was
developed in the early 1980s by amateur radio operators,
who commonly referred to this as packet radio.
The first of the IEEE Workshops on Wireless LAN was held
in 1991. At that time early wireless LAN products had just
appeared in the market and the IEEE 802.11 committee
had just started its activities to develop a standard for
2.BASIC SERVICE SET
3.EXTENDED SERVICE SET
All components that can connect into a wireless
medium in a network are referred to as stations. All
stations are equipped with wireless network interface
The basic service set (BSS) is a set of all stations that can
communicate with each other. Every BSS has an
identification (ID) called the BSSID, which is the MAC
address of the access point servicing the BSS.
An extended service set (ESS) is a set of connected BSSs. Access
points in an ESS are connected by a distribution system. Each ESS
has an ID called the SSID which is a 32-byte (maximum) character
A distribution system (DS) connects access points in an extended
service set. The concept of a DS can be used to increase network
coverage through roaming between cells.
DS can be wired or wireless. Current wireless distribution systems
are mostly based on WDS or MESH protocols, though other systems
are in use.
An ad-hoc network is a network where stations
communicate only peer to peer (P2P). There is no
base and no one gives permission to talk. This is
accomplished using the Independent Basic Service
A peer-to-peer (P2P) network allows wireless devices
to directly communicate with each other. Wireless
devices within range of each other can discover and
communicate directly without involving central
access points. This method is typically used by two
computers so that they can connect to each other to
form a network.
A bridge can be used to
connect networks, typically
of different types. A
wireless Ethernet bridge
allows the connection of
devices on a wired Ethernet
network to a wireless
network. The bridge acts as
the connection point to the
- JUN 1997 2.4 20 1,2
a SEP 1999 3.7 20 6-54
b SEP 1999 2.4 20 5-11
g JUN 2003 2.4 20 6-54
n OCT 2009 5 20 7-74
ac NOV 2011 5 160 6.93 (Gbits/s)
• Time and labor costs associated with both
wiring and installation of APs and
associated networking infrastructure.
• Higher performance, reliability, scalability
• Seamless mobility between indoor and
• Highly helpful in the places where wires
could not be set up for network.