New Types of Air Interface based on Filter Banks for Spectrum Sharing and Coexistence -- Cognitive Interference Alignment for Spectral Coexistence -- Cooperative Spectrum Sensing -- Medium Access Control Protocols in Cognitive Radio Networks -- Dynamic Channel Selection for Cognitive Femtocells -- Towards Cognitive Internet: an Evolutionary Vision -- Automatic best wireless network selection based on Key Performance Indicators -- Localization in Cognitive Radio Networks -- Challenges Towards a Cloud-RAN Realization -- A Regulatory Perspective on Cognitive Radio and Spectrum Sharing.-Simulation of Cognitive Radio Networks in OMNeT++ -- Designing a CR Test bed - Practical Issues -- Low-cost testbed development and its applications in cognitive radio prototyping.