'This is an extremely important text that comes at a critical time in the evolution of our understanding of both the characteristics of the spectrum need and the means by which this increasingly urgent need can be satisfied. [Marshall] has been one of the long term leaders in the development of the framework for dynamic spectrum access networks and cognitive radio technology, giving him a historic as well as current perspective on the challenges. The insights in this book should be of enormous value to students, active researchers, wireless systems developers, and regulatory and policy leaders.' Dennis A. Roberson, Illinois Institute of Technology '… highly original and brilliantly insightful. Preston Marshall has examined cognitive technologies under three essential key headings - scalability, density and decision-making. In doing this he unlocks the power of cognitive technologies and builds a realisable and compelling vision for communication networks of the future. Every section … is full of new ideas and insights that could only be written by someone who has been a leader in this field and has a handle on the bigger picture as well as a deep understanding of the technical details. This book is so far removed from the myriad of books that simple relate information to the reader. It is packed full of ideas, opinions and most crucially supporting evidence … a breath of fresh air … essential reading for someone who has any interest in how the challenges for communication systems of the future will be met.' Linda Doyle, University of Dublin '… a refreshing take … I strongly recommend this book to both scholars and experts in the field, and I am convinced that it will be frequently used as reference material for all interested in the future potential of cognitive wireless networks.' Shaunak Joshi, IEEE Communications Magazine