Introduction

Ever since the days of radio, wireless technology has been growing and has simplified the mode of data communication and information sharing. WLAN is another advance in technology adding to this vast and growing family of wireless technologies. As the same suggests, Wireless Local Area Network (WLAN) helps in creating wireless networks among a group of similar devices. These devices can be computers operating with different operating systems or even peripherals of a computer. What can be done using a wired connection can be done similarly using wireless technology and gives to the user of this technology freedom to roam around whether he is in office or at home.

WLANs are based on the IEEE802.11 technology standard. To be more exact,WLAN is the industrial name given to this standard which generally works on layer 1 (physical) and layer 2 (data link) of the OSI protocol stack using different modulation schemes at the physical layer and various protocols for the data link layer. The same will be discussed later in this chapter. As the frequency of communication in a WLAN system is very high, the carrier waves can even penetrate a wall of concrete and this adds to the flexibility of using this technology instead of wired technology. However, there are many challenges to this technology too such as collision of frames and the hidden terminal problem. When more than two systems come into the network, we will see, further in the chapter, how it works and the difficulties associated with it.