Three-layered prioritized cognitive radio networks with channel aggregation and fragmentation techniques

Dynamic spectrum allocation techniques are usually based on the assumption of a homogeneous cognitive radio network. In this work we describe a Continuous time Markov chain model that allows different types of bandwidth requirements and priority traffic. We have improved the lowest priority user's performance using channel aggregation and fragmentation, which are mechanisms envisioned for the LTE-A/4G standard. The evaluation consists on analytical and simulation results that have shown that pure channel aggregation performs similarly to the combined use of aggregation and fragmentation while both outperformed the fixed bandwidth approach.