Vishrutha K et.al; International Journal of Advance Research, Ideas and Innovations in Technology © 2018, www.IJARIIT.com All Rights Reserved Page | 929 ISSN: 2454-132X Impact factor: 4.295 (Volume 4, Issue 2) Available online at: www.ijariit.com Green Communications and Energy Efficiency K Vishrutha k.vishrutha2016@vitstudent.ac.in Vellore Institute of Technology, Vellore, Tamil Nadu G Janvi Sruthi janvi.sruthi2016@vitstudent.ac.in Vellore Institute of Technology, Vellore, Tamil Nadu G Vedavasu gamidivedavasu.2016@vitstudent.ac.in Vellore Institute of Technology, Vellore, Tamil Nadu T Yeswanth Reddy yeswanthreddy.2016@vitstudent.ac.in Vellore Institute of Technology, Vellore, Tamil Nadu K Manikandan kmanikandan@vit.ac.in Vellore Institute of Technology, Vellore, Tamil Nadu ABSTRACT With the advancement of technology, there is a considerable increase in the usage of mobile phones and other telecommunication devices. Today we are in the development phase of building a Smart City. People want the technology to develop further because it has influenced their living. It is very difficult for a person to survive without using a mobile phone. In the earlier days, people used pigeons for communication. With the increase in technology, many environmental problems arise because they consume power. CO2 emission has increased drastically during the last few years. CO2 emission leads to greenhouse effect which further leads to global warming. Energy efficient network technologies have to be developed which consume less power and produce a better Quality of Service (QoS). Renewable sources of energy can be used for power generation and the power generated can be effectively used by the base stations only during the active hours of the day. [1] Green communications should be implemented for the development of “An Eco-friendly Smart City”. Keywords: Green Communication, Energy efficiency, Simulator, Cognitive Radio, Renewable Energy, 5G. 1. INTRODUCTION Green Communication is used to increase the Energy efficiency by considerably reducing the Energy consumption. It provides the users with a better QoS. There has been a drastic increase in the emission of CO 2 in the last few years. According to the Carbon Dioxide Information Analysis Center, Environmental Sciences Division, Oak Ridge National Laboratory, Tennesse, United States CO 2 emissions from gaseous fuel consumption(% of total) in India was highest of all the past 54 years in 2010. The needs of the people have to be satisfied but at the same time, the Ecological Balance has to be maintained. The 3G era has been replaced by 4G and the 5G era has already begun. 4G technology cannot handle the massive increase in the users. The Fifth Generation Communication system enables the users with a high data rate, lower energy consumption and improved Quality of Service. [2] There has to be a communication link established between things to form a network. The most important challenge to achieve this is that “everything” in the network should have an ID. Due to advancements in the technology many people have started using the network and have entered the cloud. To maintain this, a better power management system has to be established that would be beneficial both to the environment and the people. Effective power consumption and quality output will lead to a city where “everything is connected” which is the basic building blocks of IoT (Internet of Things). Iot with Green communications will lead to eco-friendly communication networks. A User Equipment (UE) model has been considered. Each Base Station (BS) has a hexagonal layout and each of it has its own battery. Base stations are interconnected using optical fibers. The system is if any of the Base stations has less energy to transmit the signals then another Base station in its vicinity can share its energy. [1] Since the Base stations consume energy we can consider cluster heads (CH) instead of them.[7] This leads to less utilization of energy. Collisions in the transmission of signals can be handled by CSMA (Carrier Sense Multiple Access) algorithms. A cognitive radio (CR) can intelligently detect the free communication channels and this can be used to minimize the interference to other users. [9] In this paper we have discussed the energy efficiency of 5G networks and the differences between 5G and 4G [2], a cognitive radio