A framework of the PHY-layer approach to defense against security threats in cognitive radio networks

In this article we focus on the security in cognitive radio, which is one of the needs for new technologies requiring spectrum bands. The PHY-layer in CR is more complex than a conventional wireless communication system because of spectrum sensing and the dynamic spectrum access mechanism. Therefore, it becomes vulnerable to be invaded. We present the PHY-layer approaches to defense against security threats in CR networks. We analyze the validities and benefits of proposed approaches, which can be valid not only for the attacks in the PHY-layer but also for those in the upper layer.