Energy efficient transmission trends towards future green cognitive radio networks (5G): Progress, taxonomy and open challenges

Abstract With the growing cognizance about environmental concern and global warming-related to communication technologies, the researchers have been seeking some solutions to diminish the consumption of energy in the telecommunication industry. There is a remarkable advancement in mobile communication from simple voice-based devices to ubiquitous data-hungry smartphones. Nearly, 8 billion mobile subscribers are expected to be added by 2030 and also required an extra spectrum to serve. The existing static spectrum allocation-based technologies are not in a position to fulfill this extra spectrum requirement and handle this future traffic load. This volatile evolution of global traffic data urges research attention globally and can be handled by future cognitive radio networks. There is also a demand for providing fast speed and seamless services for which operators need to deploy more base stations continuously and increase the transmitting antenna power. As a result, a drastic hike in emissions of carbon dioxide into the environment, and exposure to harmful radiations in large amounts which is also authentically harmful to humans, animals, and birds. This increased energy consumption and scarcity of resources have made the energy as a geopolitical issue for 21 century. In this direction, this work contributes by introducing cognitive-based green communication technology to ensure the environmental and health concerns caused due to hike in the CO2 level. In the second phase, an enlightening survey on futuristic approaches for making the future wireless networks green is covered with pros and cons. In the third phase, this paper provides a framework of research challenges with ongoing project activities on green communication which further requires attention from the research community.