WIRELESS LOCAL AREA NETWORK (WIRELESS LAN / WLAN) is a local network that uses radio wave as the communication medium. In a conventional wired LAN, individual network stations are linked via some type of physical cabling. This cabling can vary from shielded copper wire to fiber-optic cable. Most office structures are wired throughout to facilitate networking using this medium. There are three major problems with physical cabling are cost, distance limitations, and mobility. The installation of any type of physical cabling requires a great deal of effort and is therefore very expensive. In addition, there are physical limitation as to the length of any given physical cabling scheme. These distances vary depending on the type of cable used, but there is always a defined maximum distance that the signal can travel along the cable before it deteriorates. To send a signal any farther than this maximum distance requires additional hardware to boost the power of the signal. Lastly, using physical cables becomes inconvenient when network users need to be mobile.

With WLAN, most of the physical cabling becomes unnecessary as you are now using radion waves to carry your signal. In a typical WLAN design, the only cables used are those necessary to connect devices that do not support wireless networks. As this technology evolves, devices that support wireless networking are becoming more prevalent and easier to find.

In order to create for a wireless system, you must consider common WLAN transmission and reception impairments such as attenuation, RF interference, and application and structural considerations. Many environmental factors can also affect your WLAN design. This section explains various common types of impairments and considerations that you may face in your wireless design and testing efforts. A lot of the issues covered here as WLAN design considerations are based on factors that can occur both indoors and outdoors. However, as a general rule, if you are looking at implementing a WLAN in a building that has been built within the last ten years and does not have any special structural considerations (i.e. concrete shielding for radiation labs), then implementing a WLAN should be pretty straight forward. There are a lot of additional factors ehen extending a WLAN over long distances outdoors, but in a standard office implementation these are usually not an issue.