Wireless LAN (WLAN) is a data transmission system designed to provide a location independent network access between the various computing devices, by using radio waves, rather than a cable infrastructure. In the present scenario, WLANs are usually implemented as the final link between the existing wired networks and a group of client computers, giving these users access to the full resources and services of the corporate network, across a building or a campus setting, without the use of cable.

WLANs offer a variety of benefits over the traditional wired networks, including productivity, convenience and cost advantages. These are highly mobile and provide access to real-time information, anywhere in the building. These networks are simple, fast and easy to install. Moreover, they provide the flexibility of taking the network where wires are difficult to pull. While the initial cost of installation of the hardware for WLANs may be higher than the wired LAN, the total cost of ownership is significantly lower, because WLANs eliminate direct costs of cabling and the labor associated with installation and repair.

Step 1: Technology Selection

Wireless technology uses radio waves to transmit data. There are several types of technologies used for data transmission. The appropriate technology for a given situation depends on the specific needs of the client. The various types of technologies are:

• n Spread-spectrum technology: Wireless products most commonly use spread-spectrum technology for data transmission. The spread-spectrum technology consumes more bandwidth than other technologies, in order to assure high reliability, integrity and security. In other words, the signal produced by the spread-spectrum is "louder" than that of other technologies.

• n Narrowband technology: A narrow-band radio system transmits and receives user information on a specific radio frequency. The radio signal frequency is kept as narrow as possible to minimize costs, through a simple radio design. The narrowband technology has a limited range, reliability and security, as compared to the spread-spectrum technology.

• n Infrared technology: Infrared (IR) systems use very high frequencies in the electromagnetic spectrum, to carry the data. Like light, infrared cannot penetrate through opaque objects. This technology has a limited range and lower throughput, as compared to the direct sequence spread-spectrum.

• n Microwave technology: Microwave technology uses low microwave frequencies that allow for range and throughput rates in between those of infrared and spread-spectrum technologies. Microwave works best with a clear line-of-sight. The FCC licensing is required for the microwave WLANs, operating between 18.8 GHz and 19.2 GHz. Line-of-sight and FCC licensing limitations, coupled with high costs and safety concerns, have inhibited the growth of microwave technology.

Step 2: Types of Wireless LANs

A Wireless LAN is comprised of Network Interface Cards (NICs), Access points and Network management. The WLAN configurations can be simple or complex. There are two basic types of WLANs:

• Peer-to-peer WLANs

• Infrastructure WLANs

Step 3a: Setting up a peer-to-peer WLAN

You only require wireless adapters on each PC, to establish a peer-to-peer WLAN.

1. Assess how many PCs need to be connected to the WLAN.

2. Equip each PC with the wireless.

3. Configure the NIC setting on each PC.

4. Whenever the PCs come within range of each other, they establish an independent network between themselves, allowing each to access the resources and information of the other.