The Study of Supporting Differentiated Services in Cognitive Radio Networks

• Main Authors: Chihda chu, 朱志達
• Other Authors: 陳偉業
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/06248784696353452035

碩士 === 南台科技大學 === 資訊管理系 === 97 === As wireless technology evolves, the number of various wireless service users increase dramatically causing the scarce radio resources more crowded than ever. However some investigations have showed that a portion of licensed spectrum was underutilized. This is due to the fact that current spectrum allocation policy was not allowed to allocate unused licensed spectrum for unlicensed users, resulting in low spectrum utilization. To solve this problem, the development of cognitive radio is an important technology. Cognitive radio network promises an effective way of enhancing spectrum usage by exploiting the unused resources of primary system, while not interfering with the transmission of primary users. Previous works are mainly focused on spectrum sensing, spectrum sharing, primary user detection, and MAC design. Few works are performed on the issues of supporting the differentiated services in cognitive radio networks. In this paper, we proposed a mechanism to guarantee the QoS of high priority users for the integrated services in cognitive radio network. Through the concept of random waiting time with priority, high priority traffic can issue channel request to base station earlier than low priority traffic, ensuring preferential channel access. The results showed that the proposed scheme can ensure high priority services having priority access to the system resources. In addition, the proposed scheme can achieve higher channel access probability and throughput than competitive mechanism scheme.