Existing "command-and-control" spectrum allocations defined by government regulatory agencies prohibit unlicensed access to licensed spectrum, constraining them instead to several heavily populated, interference-prone frequency bands. However, it has been shown that the spectrum is not utilized efficiently across time and frequency. Optimal use can be achieved by dynamic spectrum access (DSA) - the concept of unlicensed users "borrowing" spectrum from incumbent license holders temporarily to improve the spectrum utilization. Cognitive radios offer versatile, powerful, and portable...

Over the past decade the world has seen the rise of the fascinating and diverse field currently recognized as nanotechnology. This book covers a broad spectrum of topics within nanotechnology, including synthesis techniques, various innovative characterization techniques, growth mechanisms of nanomaterials, the physics and chemistry of nanomaterials, diverse functionalization methods, and the various applications of nanomaterials in biology, therapeutics, energy, food science, and environmental science. It also discusses applications of nanostructured materials, integrative applications such...