International Journal of Scientific Research Engineering &Technology (IJSRET)
Cognitive radios have become a great deal of attention in the past years. Wireless communication technology is the primary objective to improve the quality of service for the end entity. Cognitive radio is a technology capable of advancing wireless communications. Cognitive radio techniques are applied to many different communications systems. They are for increasing utilization of radio frequencies that are wasted today, allowing the improved commercial data services, and allowing for new emergency and military communications services. For example, these techniques are being considered by the U.S. Today Cognitive Radio Technology are being included by many standards such as WiFi (IEEE 802.11), Zigbee (IEEE 802.15.4), and WiMAX (IEEE 802.16). More advances are occurring in a rapid way.