Dynamic path switching routing protocol for cognitive radio networks The majority of this paper is to develop a reliable and high-performance routing protocol for cognitive radio networks (CRN). Due to the presence of the high-priority users (primary users) in the CRN, an existing routing path may easily become unavailable for any link on the path being occupied by primary users (PUs). The most intuitive way to avoid this problem is to select the path in which fewer PU activities are observed at the cost of performance sacrifice. This paper proposes a novel CRN routingprotocol which aims to maintain the performance by utilizing the high-quality link as much as possible and to alleviate the route repair cost due to the occurrence of PUs. The experimental results show that in most situations, the proposed protocol outperforms other routing protocols including one traditional and two CR routing protocols in terms of packet round-trip delay, total system throughput and packet loss rate. The results also show that the proposed protocol is very resistant to the variation of PU activities.