Improving local and collaborative spectrum sensing in cognitive networks through the implementation of cognitive collaborators

The shortage of spectrum coupled with overcrowding of unlicensed and the underutilization of licensed spectrum has led to the development of cognitive networks. Cognitive radios sense spectrum holes in licensed spectrum and utilize them when they are idle. This approach presents a number of design challenges at the MAC layer. Besides performing legacy functions, Cognitive MAC protocols coordinate spectrum sensing, spectrum decision, spectrum access and facilitate spectrum sharing between secondary (SU) and primary users (PU). Furthermore they optimize the sensing and transmission times, coordinate local and collaborative sensing. In an infrastructure-less cognitive network, nodes are expected to collaborate in spectrum sensing, to share sensing information before accessing the available spectrum, which is a challenge. To address these challenges, we propose the implementation of a cognitive collaborators scheme to coordinate local and collaborative sensing. The cognitive collaborators are equipped with two dedicated radios. One radio coordinates local and collaborative sensing and the other is employed for communication purposes. We also demonstrate through game theory technique how the use of white spaces can be optimized.