A WLAN is a LAN that uses radio waves as the physical medium. In a traditional wired LAN, individual network stations are linked via some type of physical cabling.This cabling can vary from shielded copper wires to fiber-optic cables. Most office structures are wired throughout to facilitate networking using this medium. The three main 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.The cost to wire an average sized office building can be thousands of dollars. In addition, there are physical limitations 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. A good example is a sales representative that must carry a laptop to different conference rooms to make presentations using data on the LAN. Assuming that all of the conference rooms are wired into the LAN, the sales representative would have to carry a cable to connect into any conference room that they visit, find the appropriate wall jack, and connect into the network. With a WLAN, most of the physical cabling (such as Cat 5 for client desktop connections) becomes unnecessary as you are now using radio 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.