Non-cooperative and cooperative spectrum sensing in 5G cognitive networks

5G is the expected next step of the evolution of the mobile cellular net- work, and it is considered as the answer to the ongoing huge increase of cellular users and services. The architecture envisioned for 5G includes a large number of different network entities and systems that share a common spectrum resource via a Dynamic Spectrum Access (DSA) approach. This solution is expected to significantly increase the overall spectrum efficiency, but also introduces the challenge of optimizing the coexistence between the entities forming the overall network, by limiting their mutual interference. Within this context, the Cognitive Radio (CR) paradigm, mainly focusing on its peculiar function, that is Spectrum Sensing (SS), is being currently proposed as one of the main enablers for efficient DSA with limited interference. The goal of this chapter is to provide a comparative analysis on CR-inspired Spectrum Resource Management (CR-SRM) mechanisms recently pro- posed for the 5G architecture, that mainly exploit SS, in order to characterize up- to-date research trends on the topic and highlight still-open challenges and possible future work directions.