Cognitive Radio and Dynamic Spectrum Access

Radio spectrum is today not efficiently utilized because of a complicated and time-consuming radio regulation processes and inflexibility in standardization. In this book, intelligent technologies to help overcome these barriers, namely, cognitive radios, are discussed. 90-95% of the licensed radio spectrum is not in use at any location at any given time. The existing radio regulatory regime is simply too complex to handle the increasingly dynamic nature of emerging wireless applications. As a result, we waste precious spectrum. On the contrary, the commercial success of wireless applications in open spectrum, i.e., the unlicensed bands, and the many radio systems utilizing this relatively small fraction of the radio spectrum, indicate that it may be helpful to change our so much established and manifested radio regulatory regime, towards a more flexible, open spectrum access; This discussion is the subject of the proposed book. We may just want to let radio systems coordinate their usage of radio spectrum themselves, without involving regulation. Self-organizing radio systems would then autonomously regulate in a technology-based approach: the machines would make the decisions, not humans. It can only be imagined how our economies would gain from such a flexible, technology-based approach. If successful, this approach would support new emerging wireless applications, at the same time allowing existing incumbent radio services to continue operating without Quality-of-Service degradation. Such an open approach promises to significantly increase the usage of our radio spectrum. The book is made up of eight chapters consisting of; Introduction; The Problem: Spectrum Scarcity; Todays Approaches for Spectrum Sharing; Feature Detection and Spectrum Opportunity Identification; Vertical Spectrum Sharing; Horizontal Spectrum Sharing; Cognitive Radio for Mesh Networks and; True Cognitive Radio. There are also three appendices on Software Tools, Analytical models and Game Theory.Â