Currently, the information and communications technology (ICT) industry sector accounts for about 2–6% of the energy consumption worldwide, and a significant portion of this is contributed by the wireless and mobile communications industry. With the proliferation of wireless data applications, wireless technology continues to increase worldwide at an unprecedented growth rate. This has resulted in an increased number of installed base stations and higher demand on power grids and device power usage, causing an increased carbon footprint worldwide. Current wireless industry therefore needs to embrace eco-friendly green communication technologies at different levels – from components, circuits, and devices to protocols, systems, and networks. Since the rate of improvement in power efficiency of hardware devices lags data traffic growth in both the radio access and core networks, network scaling will be increasingly tied to energy consumption in future wireless protocols, systems, and networks. Hence, it is crucial to develop green technologies for wireless systems and networks to improve energy efficiency and reduce CO2 emissions. Again, from the perspective of network operators, energy is a significant portion of their OPEX (Operational Expenses). Therefore, green radio technologies will help to reduce the operating costs of wireless networks.

Green ICT has become a critical agenda item around the world. In this context, many organizations and standard bodies throughout the world including the European Commission (EC), US Environmental Protection Agency, US Department of Energy, ISO, IEC, ITU-T, ETSI, ATIS, and the IEEE are working towards the vision of green communication networks.