Towards improving channel switching in cognitive radio networks

Since their introduction in the late 1990´s, Cognitive Radio Networks (CRNs) have received a substantial amount of interest. One of the issues that can have a negative impact on the performance of CRNs is related to the way each Secondary User (SU) chooses the channel it will use. The traditional method is to sequentially switch to channels in a round-robin manner and sense whether each channel is available or not before using it. Such an approach can cause significant degradation in the network´s performance in terms of delay and disconnections. In this work, we propose a new channel switching scheme for CRNs that takes into account both the future location of the SU and predictions about the channel availability while making the channel switching decision with the objective of reducing both the number of unnecessary switches and the number of disconnections. The results show that even with the simplest techniques to predict the future location of the SU and the availability of channels, there is an improvement over one of the widely used and studied channel switching schemes, the random scheme.