Spectrum scarcity is one of the biggest challenges that modern world is facing. Efficient use of available licensed spectrum is becoming more and more critical with increasing demand and usage of radio spectrum. Researches show that the usage is not uniform throughout licensed spectrum rather it is heavy in certain parts and has portions that are utilized inefficiently. Some researchers even claim that more than 70% of licensed frequency band is not in use, most of the time. Different researches are in progress and ways are being found to efficiently utilize the available licensed spectrum. One of the ways is the use of “Cognitive Radio”, according to this; the already licensed spectrum can be used more efficiently by introducing artificial intelligence in the radio. This enables the radio to learn from its environment, considering certain parameters. Based on this knowledge the radio can actively exploit possible empty frequencies in licensed band of spectrum that can then be assigned to other processes in such a way that they don’t cause any interference to frequency band that is already in use. This makes the efficient usage of the available licensed spectrum possible.