This is the first comprehensive analysis of one of the hottest topics in communication systems today — the application of low earth orbital (LEO) satellites in personal communication networks (PCNs). LEO satellites are the most promising tools for establishing global PCNs and yet their use can be problematic. The book describes the characteristic design features of LEO satellites, discusses the design of LEO satellite communications networks, and presents analytical frameworks for evaluating their performance. It explains the major problems relating to employing LEO satellites in a global PCN — both for today's and tomorrow's applications. The book's broad coverage, including new research viewpoints, necessary tools, and fundamental analysis techniques, will enable engineers to: identify the advantages and disadvantages of non-geostationary satellites compared to conventional geostationary systems, understand how LEO satellite systems can meet specific requirements of future global PCNs, compare different multiple access schemes — and select the newest, most promising schemes for future wireless communications and mobile satellite systems, determine the traffic characteristics of LEO satellites for global PCNs, and apply new techniques to evaluate and improve the performance of LEO satellite systems