HNC-MAC: Hybrid non-cooperative MAC protocol for independent secondary user over Cognitive Radio Networks

Cognitive Radio (CR), as a promising technique to improve the utilization of spectrum resource, has been paid much attentions. With cognitive radio technology, Secondary Users (SUs) can opportunistically access idle spectrum resource, while satisfying the Primary Users' (PUs') interference tolerance. Therefore, the integration of spectrum sensing function and dynamic spectrum access scheme is necessary in CR MAC protocol design. In this paper, we propose a Hybrid Non-Cooperative MAC (HNC-MAC) protocol for independent SU to jointly consider the spectrum sensing function and dynamic spectrum selection scheme, while limiting the level of interference to PU. Using the HNC-MAC protocol, SU can not only obtain the maximum throughput in each spectrum sensing phase under PU's collision constraint, but also perform vacant channel selection with Partially Observable Markov Decision Process (POMDP) algorithm. Furthermore, a sequence of objective factors in Cognitive Radio Networks (CRNs), such as Rayleigh fading channel between SU and PU, PU's random access and SU's practical traffic model, are also considered. Simulation results show the HNC-MAC protocol effectively improves the independent SU's throughput over CRNs.