This book gives comprehensive and balanced coverage of the principles of cognitive radio communications and networks, with details of their implementation, including the latest developments in the standards and spectrum policy. Case studies and descriptions of platforms and test beds, together with sample code, give hands-on knowledge of how cognitive radio systems can be implemented. Extensive treatment is given to the 802.22 and 802.16h (WiMAX) standards. Written by leading academic and industrial people in the field, this book gives communications engineers, R&D, engineers, researchers and graduate students a complete reference on the design and implementation of cognitive radio systems and networks.