Preface Wireless networking has emerged as its own discipline over the past decade. From cellular voice telephony to wireless access to the Internet and wireless home networking, wireless networks have profoundly impacted our lifestyle. After a decade of exponential growth, today's wireless industry is one of the largest industries in the world. At the time of this writing, close to one billion people subscribe to cellular services, close to 200 billion GSM short messages are exchanged yearly, and the penetration of the cellular telephone in Finland exceeded 75%, the highest in the world. In response to this growth, a number of universities and other educational institutions have started wireless research and teaching programs and a number of engineers and scientists are re-educating themselves in this field. There are a number of recent textbooks in the general area of networking that also address some aspects of wireless networks. The treatment in these books is not adequate because design and analysis of wireless networks are very different from wired networks. In wireless networks the complexity resides in the design of air-interface and support of mobility, neither of which play a dominant role in wired networks.

Therefore, we have always needed a comprehensive textbook on wireless networks that provides a deeper understanding of the issues specific to the wireless networks. In 1995 when wireless networking was an emerging discipline, the principal author, along with Allen Levesque, wrote the first comprehensive textbook in Wireless Information Networks that addressed cellular and PCS systems as well as mobile data and wireless LANs. Wireless-related books published prior to that book were focused on analog cellular systems. Wireless Information Networks covered 2G digital cellular systems, had significant emphasis on physical layer issues, and was written for students with background in electrical engineering, especially communications and signal processing. With the growth of the wireless industry in the latter part of the past decade, several books have emerged that explain the latest developments of specific standards or groups of standards like GSM, IS-95, W-CDMA, wireless LANs and Bluetooth. However, there is no textbook that integrates all the aspects of current wireless networks together. In this book, like the previous book, we address the need for a comprehensive treatment that provides a unified foundation of principles of all voice- and data-oriented wireless networks. The novelty of this book is that it covers 3G and wireless broadband ad hoc networking as well as 2G legacy systems, places emphasis on higher-layer communications issues, and is written for software and systems engineers as well as modern telecommunications engineers with electrical engineering or computer science backgrounds.

Traditionally, voice-oriented wireless networks have been the focus of books on wireless systems. However, with the exponential growth of the Internet, wireless data-oriented networks are also becoming very popular. The third generation (3G) wide area cellular systems are designed to support several hundreds of kbps with comprehensive coverage and up to 2 Mbps for local selected zones. Even before the emergence of 3G services, mobile data networks such as the general packet radio service (GPRS) over TDMA systems and high-speed packet data over CDMA systems are becoming increasingly popular. At the same time, after the introduction of Bluetooth technology in 1998, local broadband and ad hoc wireless networks have attracted tremendous attention. This sector of the wireless networking industry includes the traditional wireless local area networks (WLANs) and the emerging wireless personal area networks (WPANs). Wireless broadband and ad hoc networking is expected to create a revolution in the future of Internet access, home networking, and wireless consumer products. While there is a plurality o.