Ad hoc networking is a new area in wireless communications that is going to prevail in the next few decades. Understanding the full potential of this technology will lead to new applications both civilian and military, such as military ad hoc wireless networks, environmental sensor networks, car-based ad hoc networks, biomedical networks and many more. This text takes a “bottom-up” perspective. The physical layer performance of ad hoc wireless networks is studied in detail showing the strong dependence of higher layer performance on physical layer capabilities and limitations. A communication-theoretic perspective on the design of ad hoc wireless networks is presented. The interaction between physical layer and higher layers is discussed providing a new perspective in the practical design of ad hoc wireless networks. Topics in the book range from the basic principles of networking and communication systems through to applications making it ideal for practicing and R&D engineers in the wireless communications and networking industries looking to understand this new area. The inclusion of problems and solutions at the end of each chapter furthers understanding and makes it a highly relevant text for post-graduate and senior undergraduates on communication systems and computer science courses.