WLAN TECHNOLOGIES
WLAN stands for Wireless Local Area Network. WLAN is a local area
network that uses radio communication to provide mobility to the network users
while maintaining the connectivity to the wired network. A WLAN basically,
extends a wired local area network. WLAN’s are built by attaching a device
called the access point(AP) to the edge of the wired network. Clients
communicate with the AP using a wireless network adapter which is similar in
function to an ethernet adapter. It is also called a LAWN is a Local area wireless
network.
The performance of WLAN is high compared to other wireless networks.
The coverage of WLAN is within a campus or building or that tech park. It is
used in the mobile propagation of wired networks. The standards of WLAN are
HiperLAN, Wi-Fi, and IEEE 802.11. It offers service to the desktop laptop,
mobile application, and all the devices that work on the Internet. WLAN is an
affordable method and can be set up in 24 hours. WLAN gives users the mobility
to move around within a local coverage area and still be connected to the
network. Most latest brands are based on IEE 802.11 standards, which are the
WI-FI brand name.
History
A professor at the University of Hawaii who’s name was Norman
Abramson, developed the world’s first wireless computer communication
network. In 1979, Gfeller and u. Bapst published a paper in the IEE proceedings
reporting an experimental wireless local area network using diffused infrared
communications. The first of the IEEE workshops on Wireless LAN was held in
1991.
WLAN Architecture
Components in Wireless LAN architecture as per IEEE standards are as follows:
Stations: Stations consist of all the equipment that is used to connect all wireless
LANs. Each station has a wireless network controller.
Base Service Set(BSS): It is a group of stations communicating at the physical
layer.
Extended Service Set(ESS): It is a group of connected Base Service Set(BSS).
Distribution Service (DS): It connects all Extended Service Set(ESS).
Types of WLANs
As per IEEE standard WLAN is categorized into two basic modes, which are as
follows:
1. Infrastructure: In Infrastructure mode, all the endpoints are connected to a
base station and communicate through that; and this can also enable internet
access. A WLAN infrastructure can be set up with: a wireless router (base
station) and an endpoint (computer, mobile phone, etc). An office or home
WiFi connection is an example of Infrastructure mode.
2. Ad Hoc: In Ad Hoc mode WLAN connects devices without a base station,
like a computer workstation. An Ad Hoc WLAN is easy to set up it provides
peer-to-peer communication. It requires two or more endpoints with built-in
radio transmission.
Working of WLAN
WLAN transmits data over radio signals and the data is sent in the form of
a packet. Each packet consists of layers, labels, and instructions with
unique MAC addresses assigned to endpoints. This enables routing data packets
to correct locations.
How is a WLAN Created ?
A WLAN is a collection of nodes interconnected with each other for the purpose
of data sharing, transmitting messages over the internet, connecting for peer-2-
peer connectiob etc. As discussed above in types, it can be created in following 2
ways :-
1. Connecting through one base station and that could be the router that acts as
a doorway to the internet, and every other nodes (devices like computer,
smartphones) can connect to the internet and to each other through it.
2. Peer-2-Peer connection using the wifi direct technology. This is more
suitable for situations when we require to connect two or more devices
without internet and only for purpose of data exchange, connecting over a
same local network.
Is a WLAN Secure ?
Whether or not WLAN is secure depends on multiple factors of
implementation configured by the network administrator. However, by default it
has multiple security vulnerabilities. So the security team should consider all the
factor and configure accordingly.
Characteristics of WLAN
1. Seamless operation.
2. Low power for battery use.
3. Simple management, easy to use for everyone.
4. Protection of investment in wired networks.
5. Robust transmission technology.
Advantages of WLAN
1. Installation speed and simplicity.
2. Installation flexibility.
3. Reduced cost of ownership.
4. Reliability.
5. Mobility.
6. Robustness.
Disadvantages of WLAN
1. Slower bandwidth.
2. Security for wireless LANs is the prime concern.
3. Less capacity.
4. Wireless networks cost four times more than wired network cards.
5. Wireless devices emit low levels of RF which can be harmful to our health.
