Abstract
A significant part of worldwide energy is consumed by the ICT infrastructure with wireless sector to be among the main contributors to this consumption. As a result, the rising energy costs and increasing carbon footprint of operating wireless communication networks have generated a keen interest in the design and development of “green” networks, that is, networks characterized by energy efficiency, reduced CO2 emissions, and low cost deployment. In this article, we discuss current issues and trends in green wireless networking. We explain the motivation behind it, discuss basic principles, review current trends in the field, and highlight upcoming challenges and future research directions. The aforementioned issues have been treated in detail in the scientific literature. However, the present study overviews current and future trends in green wireless networking with focus on providing an insight into the field that will be useful not only for experts but for non-specialists also.
TopMotivations For Green Ict: The Wireless Networks Case
The increase in energy consumption and CO2 emissions of the ICT sector are serious issues for world economy and environmental pollution. Nowadays, the ICT market consumes 3% of worldwide energy and contributes 2% of global carbon emissions. Only in the United States, the amount of CO2 emissions due to the ICT industry was 151 MtCO2 in 2002, where 43% was due to cellular networks, while the forecast for 2020 is 350 MtCO2 with half of the emissions from the cellular infrastructure (Han et al., 2011; Suarez, Nuaymi, & Bonnin, 2012). These numbers by themselves, show the significance of the design, development and operation of energy-efficient wireless communication systems and networks.
The main objective of green wireless networking is the development of methods and techniques for the reduction of energy consumption in wireless networks. Apart from the reduced carbon emissions, the decrease in energy consumption is translated to lower operating costs in the ICT industry. Moreover, issues such as electromagnetic pollution, spectral efficiency, radio interference, and battery lifetime of mobile devices are further “green” motivations.
In order to obtain a better idea of the motivation behind the current research and future challenges in the area, it is worth mentioning to note that more than half of the energy consumption in wireless networks is due to base stations (BSs), see Figure 1; however, less than one tenth of this consumption is accounted for signal transmission, see Figure 2. Moreover, empirical data, e.g. Micallef (2010), show a slight dependence of energy consumption on traffic load.
Figure 1. Power consumption of a traditional cellular network (Adapted from Han et al., 2011)
Figure 2. Power consumption of a typical base station (Adapted from Suarez et al., 2012)
Key Terms in this Chapter
Energy Efficiency Metrics: Numeric measures used for the evaluation of energy consumption and network performance.
Long Term Evolution (LTE): A fourth generation wireless broadband technology for high-speed data transmission.
Orthogonal Frequency Division Multiplexing (OFDM): A modulation technique that splits the digital data sequence into parallel streams and then transmit them simultaneously with a large number of closely spaced orthogonal subcarriers.
Cellular Network: A wireless communications network distributed over a limited land area that includes at least one fixed position transceiver.
Cognitive Radio (CR): An intelligent radio technology that improves system efficiency by detecting available frequency bands and adaptively changing its reception and transmission parameters.
Network Optimization: The process of searching for optimal values of selected system parameters, which targets to provide network embodiments with the best possible trade-offs between specific performance metrics and costs.
Information and Communications Technology (ICT): The set of technologies that includes all computer and communication devices, systems, networks, infrastructures, applications, and services.
Carbon Footprint: The amount of CO2 emissions due to human activities.
Green Communications: Energy-efficient communication technologies primarily developed for addressing the environmental impact of traditional communication systems and networks.