Multichannel Cognitive MAC Protocol for Efficient Utilization of Wireless Spectrum

Rapid development of wireless technologies and services are increasing the demand of limited wireless spectrum. Fixed spectrum has been allocated to each application. Recent analysis shows that this scarce spectrum is not being utilized efficiently. Cognitive Radio (CR) is the developing solution of efficient spectrum utilization. Cognitive Radio is well aware of its environment and accesses the spectrum opportunistically. In this paper, we propose an efficient multichannel cognitive MAC protocol that learns the behavior of primary users on each channel and allows the secondary users to occupy the unused spectrum without any harmful interference with the primary user and with other secondary users. By using the probabilistic model, CR estimates each available channel and selects the best one for transmission. An OPNET 14 simulation scenario of coexistence of CR nodes and primary nodes of a wireless network is developed to evaluate its performance.