QoS-Adaptive Routing Protocol Design for Multi-Hop Cognitive Radio Networks Considering Multi-Link Interference

Recently, cross-layer routing design for cognitive radio networks (CRNs) has been studied widely. However, none of the previous literatures discuss multi-link interference (in routing protocol design), which results in queuing delay and backoff delay. A large queuing and backoff delay will reduce the transmission efficiency of a link and increase the cumulative end-to-end delay. In this paper, we first propose a multi-link interference model, and derive the transmission efficiency of a link. Then, in order to improve the transmission efficiency (thus the quality of service) under multi-link interference situation, we propose a source routing protocol based on on-demand routing and dynamic channel assignment. The channel assignment tries to maximize the transmission efficiency of links along the selected path. Hence, our proposed routing protocol can reduce the average cumulative end-to-end delay of all flows and increase the packet delivery ratio.