부산대학교 도서관

Recent developments of the wireless communication technology lead to the problem of growing spectrum scarcity and spectrum shortage. Most of the frequency spectrum has already been licensed by the government agencies such as Federal Communications Commission (FCC). There exists a spectrum scarcity for new wireless applications and different services. Cognitive radio (CR) is used to solve the spectrum scarcity problem by utilizing the spectrum dynamically. Cognitive Radio can utilize the unused or free spectrum for the secondary usage without interfering a primary licensed user. The cognitive radio network is vulnerable to several harmful attacks launched intentionally or unintentionally. Because of different attacks, security in cognitive radio networks is still an open challenge. The main focus of this research paper is to detect selfish node in cognitive radio network. Here, a method which uses Credit Risk Value (CRV) is being proposed to identify the selfish users to improve the network performance.