Simulation model of spectrum handoff process for medium access control protocols in cognitive radio networks

Cognitive radio is a new technology that improves spectrum utilization by allowing secondary users to use licensed channels in an opportunistic manner. Because primary users have a right to use their licensed channels at any time, it is necessary for secondary users to stop their transmissions or to continue their transmissions in other channels in case of action of primary users. The event of changing channel for secondary users is known as spectrum handoff. Spectrum handoff for medium access protocols is an emerging topic because of the increasing spectrum scarcity. In this paper, simulation model of a cognitive radio network that consists of primary users and secondary users is considered. Riverbed Modeler Simulation Software is used for simulation scenarios. Secondary users are designed to make spectrum handoff between time slots of primary users with reactive decision spectrum handoff. It is clearly seen that number of handoff is significantly decreased by means of instant sensing based reactive spectrum handoff.