Effective peer-to-peer routing in heterogeneous half-duplex and full-duplex multi-hop cognitive radio networks

This paper proposes an adaptive routing and spectrum assignment protocol for heterogeneous Full-duplex (FD) and half-duplex (HD) cognitive radio (CR) networks. The key design goal of the developed protocol is to select a path between a source-destination pair, and to optimally assign channels to each hop along the selected path. One main feature of the proposed protocol is that it takes into account the dynamic activity of Primary Users (PUs) over radio channels. To that end, radio channels are characterized in terms of their average availability-time, and the proposed protocol selects the channels with maximum availability-time. Another main feature of the proposed protocol is considering network heterogeneity, where the connected devices may have HD or FD transmission capabilities. The proposed protocol follows a segmentation strategy that relies on the existence of HD nodes. It choses the path with least number of path-segments (and hence minimum HD nodes) to minimize the likelihood of time-shared transmissions, and hence improves network throughput. Compared to existing FD-based schemes, simulation results show that the proposed routing scheme provides considerable enhancement on the overall network performance.