Channel assembling strategy in cognitive radio networks: A queuing based approach

摘要

With channel assembling strategies (CAS), more capacity and spectrum utilization can be achieved. However, blocking and forced termination occurs whenever the primary user (PU) arrives individually, or in batch. Motivated by a realistic scenario in cognitive radio networks, we proposed a joint CAS with queue (CAS+Q) which take into account the dynamics of a wireless link and other factors that affect the quality and capacity of the accessible channel. For CAS+Q to be practical, it must consider the time varying wireless link, a finite buffer regime, the traffic classes and adaptive modulation and coding (AMC) scheme. The introduction of a queuing regime for secondary users (SUs) is to ensure that traffic that would have been blocked or forcibly terminated would otherwise be queued in a buffer and possibly served later. This is to improve spectrum utilization and more especially, minimize blocking and forced termination of the SUs services. An investigation of the proposed strategy (CAS+Q) featuring AMC showed improved system performance when compared to our previous study without a queuing regime. It also showed the impact of delays on the proposed strategy depending on the system parameters selected. Extensive system simulations validate the analytical investigation.