In modern day wireless networks, spectrum utilization and allocation are static. Generally, static spectrum allocation is not a feasible solution considering the distributed nature of wireless devices, thus some alternatives must be ensured in order to allocate spectrum dynamically and to mitigate the current spectrum scarcity. An effective solution to this problem is cognitive radio (CR), which seeks the empty spectrum portions and shares them with the neighboring devices. The CR devices can utilize the available spectrum more efficiently if they try to work together. Therefore, in this work, we review a number of dynamic spectrum allocation techniques, especially those using multiagent systems and game-theoretical approaches, and investigate their applicability to CR networks. The distributed nature of these two domains makes them suitable for CR networks. In fact, the idea of dynamic spectrum sharing using these techniques is not entirely new and several interesting approaches already exist in literature. Thus, in our study we try to focus on existing spectrum sharing literature and cooperative multiagent system for CR networks. We are particularly interested in showing how the distributed nature of multiagent system can be combined with cognitive radios in order to alleviate the current static spectrum usage as well as maintaining cooperation amongst the CR nodes. Moreover, our work includes the description of various scenarios in which spectrum sharing is an essential factor and hence must be performed in a dynamic and opportunistic manner. We also explain the working of our proposed spectrum allocation approach using multiagent system cooperation in one of these scenarios and verify its formal behavior using Petri net modeling.
COGNITIVE RADIOS FOR DYNAMIC SPECTRUM ACCESS - Dynamic Spectrum Sharing: A Game Theoretical Overview
