OVERVIEW

Future wireless networks will enable people on the move to communicate with anyone, anywhere, at any time, using a range of multimedia services. The exponential growth of cellular telephone and paging systems coupled with the proliferation of laptop and palmtop computers indicate a bright future for such networks, both as standalone systems and as part of the larger networking infrastructure.

This chapter describes wireless networks. Section 7.1 provides an introduction to these networks, including their history and prospects, and the technical challenges of design and operation posed by the underlying wireless channel. Section 7.2 presents the main characteristics of the wireless channel and their impact on the link and network layer design. Link layer design techniques developed to overcome wireless channel impairments to delivering high data rates with low distortion are described in Section 7.3.

The wireless channel is a limited resource that is shared among many users. Section 7.4 is devoted to channel access protocol. Section 7.5 outlines design issues for wireless networks, including network architecture, user location and routing protocols, network reliability and QoS, internetworking between wireless and wired networks, and security.

Current wireless network technology is described in Section 7.6 including cellular and cordless telephones, wireless LANs and wide area data services, paging systems, and global satellite systems. Section 7.7 gives an overview of emerging systems and standards for future wireless networks. Section 7.8 contains a summary and a discussion of future trends.

7.1 INTRODUCTION

Wireless communications is the fastest growing segment of the communications industry.