Green 5g Enabling Technologies: An Overview

Given the rising concerns on carbon emission and increasing operating expense pressure, mobile network operators and device vendors are actively driving the energy-efficient network evolution. Energy efficiency (EE) has been determined as one of the key objectives of the 5G system. To realise sustainable 5G, various new technologies have been proposed to reduce conventional energy consumption. Meanwhile, green energy sources are explored to reduce the dependence on conventional energy. This study makes a survey on recent academia and industry research on the EE of the 5G system from perspectives of radio resource management, architecture and deployment paradigm, green energy harvesting and smart grid integration. Typical green 5G enabling technologies are presented and discussed comprehensively. Moreover, the latest progress on EE in 3GPP is also investigated. Given the broad research areas, only those critical open issues and challenges are presented to inspire further investigations. Finally, the authors identify several research directions as the way forward to realise the green 5G system.