Cognitive Radio Networks

A cognitive radio can be defined by the capability of being aware of its environment and the internal state and, based on the knowledge of these elements and any stored pre-defined objectives, can dynamically adapt, make, and implement decisions about its behavior. Among the applications of cognitive radio, the most widely explored regards the improvement of spectrum bands usage, also known as white spaces. This paper presents a review of cognitive radio framework that facilitates the understanding and implementation of spectrum management functions of a typical-cognitive radio network project.