Spectrum sharing in cognitive radio networks : towards highly connected environments The wireless communication world exemplifies the swift transformation towards 5th generation cellular networks the rapid shift from user centric to device centric communication which has created a tremendous impact on service complexity and network requirements. The forthcoming networks present essential demand of ubiquitous throughput low latency and high reliability and are also intended to provide energy efficiency spectrum reuse network scalability and robustness as well as improved quality of user experience which proves to be of ultimate importance. Therefore the government academic and industrial institutions are working together to fulfil these challenging issues