The role of radio LANs in the wireless evolution

The wireless communication landscape will continue to develop at a rapid pace over the next years. New systems and standards are on the horizon, which enable broadband wireless communication in the office, at home, and "on the move". They will finally bring the information services provided by the Internet and the World-Wide-Web also to the mobile users, together with a variety of multimedia entertainment services. In this paper we give an overview of key developments in wireless communication systems. The emerging 3rd generation cellular systems and the growing importance of wireless local-area and personal-area networks are discussed. The physical and medium-access control (MAC) layer of the new broadband wireless LANs which enable "hot-spot" data and multimedia services in airports, hotel lobbies, and a variety of other "public" places are presented. We give an outlook towards a future 4th-generation wireless communication system, which can be integrated with the IP backbone network and provides Quality of Service (QoS) support for multimedia applications. It supports dynamic scheduling, link adaptation, and frequency selection in addition to full mobility support. Finally, we illuminate some of the underlying technology developments driving the wireless evolution.