In recent years, the desire for connectivity has caused an exponential growth in wireless communication. Wireless data networks, in particular, have led this trend due to the increasing exchange of data in Internet services such as the World Wide Web, e-mail, and data file transfers. The capabilities needed to deliver such services are characterized by an increasing need for data throughput in the network; applications now under development, such as wireless multimedia distribution in the home, indicate that this trend will continue. Wireless Local Area Networks (WLANs) provide an example of this phenomenon. The original (1997) Institute of Electrical and Electronic Engineers (IEEE) WLAN standard, 802.11, had a gross data rate of 2 megabits per second (Mb/s);

the most popular variant now is 802.11b, with a rate of 11 Mb/s;

and 802.11a, with a rate of 54 Mb/s, is now entering the market.