The authors would like to acknowledge the many individuals and organizations that helped in the preparation of this text. The National Science Foundation provided funding (DUE-0341209) to allow time to write. Special recognition is extended to the Global Wireless Education Consortium (GWEC) and its administrators, Misty Baker and Susan Sloan, for their support in establishing the concept for the book and for advice along the way. Special thanks is also due to Gerald DiPiazza and Richard Frenkiel, two early pioneers responsible for the development of cellular communications, for their contributions to the text and their insightful comments. Gerald provided a thermal noise analysis for an early cellular mobile unit and Richard provided the splendid overview of the history of wireless communications in Chapter 1. We wish to express our sincere appreciation for the enthusiastic support of the folks at Award Solutions, Inc. In particular, we thank Russ Edwards, Hooman Razani, Chris Reece, and Nishith Tripathi, for their helpful discussions on contemporary systems and their evolution, and Satyajit Doctor and Ramki Rajagopalan, for their support of GWEC and the creation of this book. We also thank Andy Groome, of Groome Technologies, for his helpful discussions on current practice for creating link budgets and for providing some real-world examples.