Primary User Emulation attack and their mitigation strategies: A survey

Cognitive Radio emerged as a solution to solve the spectrum scarcity by allowing unlicensed user to exist with the licensed users of the network whenever the licensed users are in idle state. Cognitive radio since its inception has received a lot of importance as far as research is concerned, however security threats also emerged with this promising technology among which Primary User Emulation (PUE) attack is one. We cover an understanding of the PUE attack in this paper and then discuss existing solutions to mitigate it along with the limitations of the proposed solutions. In end we identify the need of solution to address a case that has not been addressed yet.