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Reviewer: William W. Oblitey

Mobile communications has grown so rapidly that many people need to understand the technology and its benefits. This comprehensive introduction to mobile communications technology is suited both to students and to networking professionals. It is, however, directed more toward computer scientists than toward electrical engineers. The book explores the need for mobile communications and argues that, for many countries, it is the only communications solution, due to the lack of an appropriate fixed infrastructure. Schiller thus introduces the field of mobile communications and focuses heavily on digital data transfer. The book is well written and follows the ISO/OSI reference model in explaining the technology, but some portions read like direct translations from German into English. The author could also have done better by staying away from such questionable terms as “slave” and “master” and instead used primary/secondary, client/server, or other less nervous terminology. The book consists of 11 chapters, endnotes that elaborate on various points covered in the text, an appendix of acronyms, and an exhaustive index. Chapter 1, the introduction, explains the need for mobile communications and provides a quick overview of the technology and of the contents of the book. Chapter 2 explains wireless transmission. Topics include systems sharing the same frequencies; antennas; and the usual topics of signal propagation, signal modulation and propagation schemes, spread spectrum, and cellular systems. The author explains the standard multiplexing schemes that can increase the capacity of the medium, and introduces the concept of cellular systems. Chapter 3 presents several medium access control (MAC) algorithms specifically adapted to the wireless domain. The chapter explains why special MAC schemes are needed in wireless networks, and why the standard MAC schemes used in wired networks often fail. The author makes the case for combining schemes instead of using them in their pure form. The hidden and exposed terminal problems are explained thoroughly. Chapter 4 presents Global System for Mobile communications (GSM) as the most successful digital cellular network, showing its evolution from voice transmission toward a more data-oriented transfer system, and from a circuit-switched networking system to a packet-switched one. The chapter also discusses other systems, including the digital standard for cordless phones and the trunked radio system, and explores the differences between standards employed in the US and in Europe. Chapter 5 discusses satellite communication and its support of wireless communications. After presenting the history of satellite development and different areas of application, Schiller discusses the basics of satellite systems. Chapter 6 covers unidirectional broadcast systems within future communication scenarios and discusses their cost effectiveness. It provides a general introduction to asymmetric communication, up to the extreme case of unidirectional broadcasting, detailing digital audio broadcasting and digital video broadcasting. Chapter 7 discusses various technologies designed for wireless local area networks (WLANs)—HYPERLAN, IEEE 802.11 WLANs, and Bluetooth—and their basic goals and differences. This chapter also paves the way for chapter 8, which presents an overview of Wireless Asynchronous Transfer Mode (WATM) technology. It describes current WATM standardization efforts, discusses the motivation for WATM, lists several services that WATM should provide, and defines some scenarios that, in the author's opinion, should be supported by WATM. Several aspects of WATM and mobility extensions required in the fixed ATM network are also described. Chapter 9 introduces network-layer protocols and mechanisms to support mobility. The author gives an overview of mobile IP and its security, efficiency of packet flow, and support for quality of service. He also discusses the dynamic host configuration protocol and its inherent problems. Next, he considers ad hoc networks, which offer a completely new way of setting up mobile communications where no infrastructure is available. This, in turn, leads to a discussion of routing, since these networks have no base station that can reach all stations via broadcast, as in cellular networks. Chapter 10 introduces the problems of Transmission Control Protocol (TCP) as a connection-oriented protocol in a mobile communications environment. The author does not argue with the fact that User Datagram Protocol (UDP) will work in a mobile environment, but he makes the case for the robustness of TCP and discusses the mechanisms that play a role in using TCP for mobile networks. Finally, chapter 11 focuses on file systems and the World Wide Web as examples of applications that make a communication network useful. The attractiveness of the Web and the increasing number of people using wireless communications on the Web lead to several problems, which are addressed here. The majority of the chapter cover s the Wireless Application Protocol as a framework comprising several communication layers, a markup and scripting language, and a connection to the telephone network. I recommend this book to anyone teaching an introductory course on mobile communications.