Challenges in Energy-Efficient Communications as Enablers for Green Solutions on the 5G Heterogeneous Networks

Introduction

Nowadays, there is an interest on technology development in the growing area of green communications for reducing energy consumption in wireless communications. Some works reported in literature claim that there will be an increase of CO₂ equivalent emissions by a factor of three until 2020 compared to 2007 (Uriarte-Ramírez & Barboza-Tello, 2014). Societal development will lead to changes in the way mobile and wireless communication systems are used. This has accelerated the implementation of 5G networks that can provide exponentially more capacity, lower latency, ubiquitous connectivity, as well as increased reliability and availability. Those 5G future services such as e-banking, e-learning, and e-health will continue to proliferate. On-demand information and entertainment (e.g. in the form of augmented reality) will progressively be delivered over mobile and wireless communication systems. These developments will lead to an avalanche of mobile and wireless traffic volume predicted to increase a thousand-fold over the next decade (Osseiran, et al., 2014). Thus, those multimedia application services must cope with high data rate demands. However, higher data rates necessitate more energy per bit for a given bit error rate (BER), which in turn increases the overall energy consumption of the system and the production of CO₂ emissions that are threat to global warming. Thus, researching energy-efficient designs for high data rate wireless communication systems is a burning issue. Due to escalating expansion of wireless network infrastructures and exponential growth in traffic rate, a considerable amount of worldwide energy is consumed by Information and Communications Technology (ICT) of which more than 70% is being used by radio access part/radio frequency (Mohammad S. & Alagan Anpalagan, 2013) . Climate change and the need to reduce global energy usage are now accepted. Today 4 billion of people on the earth have access to a mobile phone; effective access to information and communications is a proven stimulus to economic development. Recent studies have shown the potential for IT (Information Technology) to reduce energy consumption in other industries. As a key enabler of green solutions on environmental an economic grounds, more energy efficient radio access networks are required. When it is about the power, the consumption of a mobile handset per subscriber is lower than the base station. However manufacturing energy is a larger component in the mobile handset that in the base station. It is mainly due to the fact that lifetime of a base station is longer (typically 10-15 years) compared to a handset (approximately 2 years) (Pollin S., et al., 2008).