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Proactive spectrum handoff performance evaluation model for Cognitive Radio

In this paper considered spectrum mobility techniques for cognitive radio that based on spectrum sensing. Cognitive Radio (CR) is the newest technology to make the secondary users to make use of licensed spectrum in the opportunistic manner. In the proposed structure, politics of switching channel and a proactive spectrum handoff protocol are let cognitive users use a channel before a primary user occupy it to avoid unwanted interference. Network coordination techniques for cognitive users are also included into the spectrum handoff protocol design to realize channel collision. In the reactive spectrum handoff type, secondary users transmit a packet without predicting the availability of the current channel at the moment when a frame ends. Here is compared the capacity of proposed proactive spectrum handoff scheme with the reactive spectrum handoff type. Proactive spectrum handoff always shows better performance than reactive spectrum handoff in terms of highest capacity and lower collision rate.