An admission control scheme for secondary users in cognitive radio networks

Recently, cognitive radio (CR) has been proposed to promote the efficient utilization of the spectrum by exploiting the spectrum holes. The fundamental issue in cognitive radio (CR) networks is the efficient utilization of radio resources. Call admission control (CAC), which controls the number of calls based on the available resources and bandwidth, is an important functionality to ensure the quality of service (QoS). Thus, in this paper, a new call admission with eviction control of secondary users (CAEC) is proposed to improve the spectrum utilization efficiency. This proposed scheme provides better balance between SU QoS and primary users (PUs) protection. Performance evaluation is conducted in terms of the quality of service (QoS) requirements, such as useful utilization and loss probability. Numerical results show that the proposed CAEC achieves higher admitted traffic for SUs and ensure higher system utilization.