With the expansion of the cognitive radio and spectrum sensing techniques, an extensive number of applications based on these technologies are evolving. New wireless services and applications (such as 5G and cognitive radio, among others) appear in the market due to microelectronics advancements and embedded computing being added to portable devices (Carvalho and Vasconcelos 2014).
New services, based on spectrum sensing applications (such as TV white spaces allocation, cognitive vehicular networks, health care and emergency networks, 5G, smart grids, and power line communications (Carvalho et al. 2014b)) are described in the sequel.
4.1 TV WHITE SPACES
The whole frequency spectrum present white spaces ...