Mitola's view on the future of Cognitive Radio
[...] DoD [United States Department of Defense] is moving into the age of dynamic spectrum access (DSA), which is the key near-term contribution of cognitive radio. Industry leaders like Nokia have adopted cognitive radio within allocated spectrum bands to more effectively manage heterogeneous spectrum and femtocell dynamics, moving network intelligence to the radios [...]"
and the second about the challenges left in cognitive radio systems
[...] There are no key challenges in spectrum sensing at the physical layer. [...] the major issues have to do with market structure and not technology per se. The FCC spectrum occupancy database ruling removed regulatory barriers, so the key issues now have to do with cognitive networks, particularly of the integration of space-time-RF databases into cognitive networks."