Green networks: Energy efficient design for future generations of wireless networks

Abstract

Background & Objectives: Qatar ranked number one in the world in terms of per capita CO2 emissions and is the latest Middle Eastern country to aggressively push towards reducing the per capita CO2 emissions and embrace a low carbon economy. Information and communication technology (ICT) already represents around 2% of total CO2 emissions (of which wireless networks represents about 0.2%) and this is expected to increase annually. The exponential growth in demand for higher data rates in wireless networks requires dense deployment of base stations which not only increases the energy consumption but also requires higher capital expenditures which still do not ensure an improvement in the data rate. To address the challenges of increasing the energy efficiency of the future wireless networks and maintain profitability, it is essential to consider various novel technologies which improve the energy efficiency of wireless networks and establish 'greener' networks. Therefore, decreasing the propagation distance between the base station and the mobile users is a promising solution to design energy aware wireless networks. Methods: Small cells such as femtocells are becoming a standard part of future wireless networks. We propose an energy aware design for wireless networks where the small cells are arranged around the edge of the macrocell such that the configuration is referred to as cell-on-edge (COE) where mobile users transmitting with a reduced transmitter power enjoy higher data rates due to shorter distances between the transmitter and the receiver. The COE configuration promises energy savings by integrating small cell and macrocell networks and thereby reducing CO2 emissions, operational and capital expenditures whilst enhancing the spectral and energy efficiency of wireless network. In this context, we define a performance metric which characterizes the aggregate energy savings per unit macrocell area and is referred to as an area green efficiency (AGE) wireless network. Results: The proposed wireless network design will provide a significant increase in energy efficiency of approximately 50% to 75% in comparison with the existing networks. Conclusions: The COE configuration has been shown to reduce CO2 emissions and thereby significantly improve the energy efficiency of future wireless networks.