Preface The field of wireless networks has witnessed tremendous growth in recent years and it has become one of the fastest growing segments of the telecommunications industry. Wireless communication systems, such as cellular, cordless and satellite phones as well as wireless local area networks (WLANs) have found widespread use and have become an essential tool to many people in every-day life. The popularity of wireless networks is so great that we will soon reach the point where the number of worldwide wireless subscribers will be higher than the number of wireline subscribers. This popularity of wireless communication systems is due to its advantages compared to wireline systems. The most important of these advantages is the freedom from cables, which enables the 3A paradigm: communication anywhere, anytime, with anyone. For example, by dialing a friend or colleague’s mobile phone number, one is able to contact him in a variety of geographical locations, thus overcoming the disability of fixed telephony. This book aims to provide in-depth coverage of the wireless technological alternatives offered today. In Chapter 1, a short introduction to wireless networks is made. In Chapter 2, background knowledge regarding wireless communications is provided. Issues such as electromagnetic wave propagation, modulation, multiple access for wireless systems, etc. are discussed Readers who are already familiar with these issues may skip this chapter. In Chapter 3, the first generation of cellular systems is discussed. Such systems are still used nowadays, nevertheless they are far from being at the edge of technology. Chapter 3 discusses two representative first generation systems, the Advanced Mobile Phone System (AMPS) and the Nordic Mobile Telephony (NMT) system. In Chapter 4, the second generation of cellular systems is discussed. The era of mobile telephony as we understand it today, is dominated by second generation cellular standards. Chapter 4 discusses several such systems, such as D-AMPS, cdmaOne and the Global system for Mobile Communications (GSM). Moreover, data transmission over 2G systems is discussed by covering the so-called 2.5G systems, such as the General Packet Radio Service (GPRS), cdmaTwo, etc. Finally, Chapter 4 discusses Cordless Telephony (CT) including the the Digital European Cordless Telecommunications Standard (DECT) and the Personal Handyphone System (PHS) standards. Chapter 5 discusses the third generation of cellular systems. These are the successors of second generation systems. They are currently starting to be deployed and promise data rates up to 2 Mbps. The three different third generation air-interface standards (Enhanced Data Rates for GSM Evolution (EDGE), cdma2000 and wideband CDMA (WCDMA)) are discussed. Chapter 6 provides a vision of 4G and beyond mobile and wireless systems. Such systems target the market of 2010 and beyond, aiming to offer data rates of at least 50 Mbps. Due to the large time window to their deployment, both the telecommunications scene and the services offered by 4G systems and beyond are not yet known and as a result aims for these systems may be changing over time. Chapter 7 discusses satellite-based wireless systems. After discussing the characteristics of the various satellite orbits, Chapter 7 covers the VSAT, Iridium and Globalstar systems and discusses a number of issues relating to satellite-based Internet access. Chapter 8 discusses fixed wireless systems. The main points of this chapter are the well- known Multichannel Multipoint Distribution Service (MMDS) and Local Multipoint Distri- bution Service (LMDS). Chapter 9 covers wireless local area networks. It discusses the design goals for wireless local area networks, the different options for using a physical layer and the MAC protocols of two wireless local area network standards, IEEE 802.11 and ETSI HIPERLAN 1. Further- more, it discusses the latest developments in the field of wireless local area networks. Chapter 10 is devoted to Wireless Asynchronous Transfer Mode (WATM). After providing a brief introduction to ATM, it discusses WATM and HIPELRAN 2, an ATM-compatible wireless local area network. The chapter also provides a section on wireless ad-hoc routing protocols. Chapter 11 describes Personal Area Networks (PANs). The concept of a PAN differs from that of other types of data networks in terms of size, performance and cost. PANs target applications that demand short-range communications. After a brief introduction, Chapter 11 covers the Bluetooth and HomeRF PAN standards. Chapter 12 discusses security issues in wireless networks. Security is a crucial point in all kinds of networks but is even more crucial in wireless networks due to the fact that wireless transmission cannot generally be confined to a certain geographical area. Chapter 13 deals with the basics of simulation modeling and its application to wireless networking. It discusses the basic issues involved in the development of a simulator and presents several simulation studies of wireless network systems. Finally, Chapter 14 discusses several economical issues relating to wireless networks. It is reported that although voice telephony will continue to be a significant application, the wireless-Internet combination will shift the nature of wireless systems from today’s voice- oriented wireless systems towards data-centric ones. The impacts of this change on the key players in the wireless networking world are discussed. Furthermore, the chapter covers charging issues in the wireless networks. We would like to thank the reviewers of the original book proposal for their constructive suggestions. Also, we would like to thank our students for some feedback that we received while trying the manuscript in class. Many thanks to Wiley’s editors and editorial assistants for their outstanding work. Wireless Networksxvi . issues in wireless networks. Security is a crucial point in all kinds of networks but is even more crucial in wireless networks due to the fact that wireless. application, the wireless- Internet combination will shift the nature of wireless systems from today’s voice- oriented wireless systems towards data-centric ones.