STAR: STAble routing for hidden interfering primary user problems in mobile cognitive radio networks

In mobile Cognitive Radio Networks (CRNs), the frequent link breakage and wireless interference urged the need for novel stable routing solutions. In this paper, we propose STAR, a stable routing protocol that aims at selecting interference-free and durable paths. We investigate the particular Hidden interfering Primary User (HIPU) problem caused by the un-detectable presence of the primary user in the transmission range of the secondary users resulting on severe packet loss. While existing CRNs routing solution, generally, overlook the interference caused by the Hidden Interfering Primary User (HIPU), STAR defines a HIPU-free transmission zone, that enables successful transmission and selects a stable route that is free from interference along the path to the destination. STAR uses prediction based model to estimate the link stability and the link propagation delay. To quantitatively select the best stable links along the route, STAR implements an objective function, cognitive stable link (CSL), that captures node mobility, interference by the HIPU, link propagation delay, and the distance towards the destination. We evaluate STAR, while comparing its throughput, latency, and packet loss ratio to three other protocols, namely PCTC, J-SRCA and AODV. Evaluation on MATLAB shows that STAR achieves higher throughput while reducing the end-to-end latency and the packet loss in the network.