TABLE OF CONTENTS In order to successfully test something, it is essential to have a good understanding of how it works and what it does. We will therefore begin with an introduction to the important technical factors behind IEEE 802.11 wireless LANs (WLANs), as well as the standards and regulatory documents that govern how WLANs are developed and operated. By necessity, only brief explanations can be provided here; the reader is encouraged to consult the actual standards documents and other references for more information.
Contrary to popular misconception, 802.11 is not merely "wireless Ethernet." Instead, 802.11 WLANs use an entirely different network protocol and are deployed in different topologies. The purpose of a WLAN is primarily to provide LAN connectivity to portable and mobile stations (laptop computers, voice handsets, bar-code readers, etc.), though fixed-station use is becoming more popular as the technology becomes widely adopted.
Essentially, WLANs provide data communications over radio links, and are subject to all the vagaries of RF propagation and interference that any radio communications system suffers. Wired (optical or copper) LAN links are nearly error-free (normal bit error rates are on the order of 1 10 9), physically secure, independent of environmental influences or mutual interference, and provide extremely high bandwidth. A single optical fiber, for instance, is capable of supporting hundreds of gigabits/second of bandwidth. By contrast, radio links are subject to error rates as high as 10%, subject to both eavesdropping and denial of service, highly affected...
