Detecting Selfish Secondary User for Improving the Performance of Cognitive Radio Network by Using Sad Method

Cognitive radio (CR) is an opportunistic communication technology which is designed to utilize the maximum available licensed bandwidth for unlicensed users. In CR, when the spectrum is not used by primary user, it is accessed by the unlicensed users/secondary users. . In CRN a selfish SU (secondary user) broadcasts faked channel allocation information to other neighboring SUs in order to occupy all or a part of the available channels which results in severe denial of service (DoS) to CRNs. This leads to a new security threat known as the primary user emulation (PUE) attack that raises a great challenge to CRNs. So, in order to overcome this problem an innovative technique is proposed named as Selfish Attacks Detection (SAD) method to identify the selfish secondary users in the cognitive radio network. The technique detects the attacks of selfish SUs by the cooperation of other legitimate neighboring secondary users which detects only single malicious user. So, Distributed reaction mechanism is added to detect more than one selfish node. Two reaction mechanisms are proposed based upon local information, to prevent selfish misbehaviors in cognitive radio adhoc networks. The technique achieves detecting more than one selfish node and reduces the degradation in the performance of the cognitive radio networks. The main contribution of work is to improve the performance of the cognitive radio network and to detect the attacks very efficiently. An experimental result shows that the proposed method achieves high packet delivery ratio, high throughput and less delay.