Trends in local wireless data networks

This paper starts with a review or historical trends in the field of wireless local area networks, including issues of regulation and standards. The most important technical issues for wireless LANs are also discussed. Trends in applications are described, including the vision of wireless local area networks moving beyond the “LAN extensions” that were the most important applications of first-generation wireless LAN products, and finding a market in the field of mobile computing. Then the paper presents two of the more important transmission-related issues of interest to mobile users; power usage and data rate. The tradeoff between power consumption and data rate is studied in the context of five transmission techniques that have been considered by wireless LAN standards bodies; direct sequence and frequency hopping spread spectrum, multicarrier modulation, decision-feedback equalization, and sectored antenna systems