vation behind this book, which aims to give the reader an insight into these technologies of sufficient depth to gain an understanding of the fundamentals and appreciate the diversity, while avoiding getting down to the level of detail that would be required by a system developer. As well as seeking to appeal to the reader who wants to gain this technical insight, the book also aims to use this understanding of the principles of wireless networking technologies as a foundation on which, a discussion of the practical aspects of wireless network implementation can be grounded. Organisation of the Book This book is arranged in seven parts, with Parts I and II providing an introduction to wireless networking and to wireless communication that lays the foundation for the more detailed, technical and practical discussion of the local, personal and metropolitan areas scales of wireless networking in Parts III to V. Part I - Wireless Network Architecture - introduces the logical and physical architecture of wireless networks. The 7 layers of the OSI Chapter One network model provide the framework for describing the protocols and technologies that constitute the logical architecture, while wireless network topologies and hardware devices are the focus of the discussion of the physical architecture. Some of the key characteristics of wired networking technologies are also briefly described in the two chapters of Part I, in order to provide a background to the specific challenges addressed by wireless technologies. In Part II - Wireless Communication - the basics of wireless communication are described; spread spectrum, signal coding and modulation, multiplexing and media access methods and RF signal propagation including the important topic of the link budget. Several new or emerging radio communication technologies such as ultra wideband, MIMO radio and Near Field Communications are introduced. Part II closes with a similar overview of aspects of infrared communications. Part III - Wireless LAN Implementation - focuses on