Energy Self-Sustainability in Full-Spectrum 6G

Full-spectrum ranging from sub-6 GHz to THz and visible light will be exploited in 6G in order to reach unprecedented key-performance-indicators. However, an extraordinary amount of energy will be consumed by network infrastructure, while functions of massively deployed Internet of Everything (IoE) devices are limited by embedded batteries. Therefore, energy self-sustainable (ESS) 6G is proposed in this article. First of all, it may achieve network-wide energy efficiency by exploiting cell-free and airborne access networks as well as by implementing intelligent reflecting surfaces (IRSs). Second, by exploiting radio-frequency/visible-light signals for on-demand wireless information and energy provision (WIEP) and for enabling passive backscatter communication, “zero-energy” IoE devices may become a reality. Furthermore, IoE devices actively adapt their transceivers for better performance to a dynamic environment. Case studies of cell-free and IRS based WIEP are provided for demonstrating the advantage of our proposed architecture in terms of energy self-sustainability. This article aims to provide a first glance at primary designing principles of ESS-6G.

Introduction

With 6G going toward higher spectrum (such as Tera-Hertz or THz) and thus resulting in even denser networks and smaller cells, energy consumption will become a big hurdle on the way to 6G success [1]. On the infrastructure side, a huge amount of energy will be consumed for powering numerous radio-frequency (RF) chains connected to a vast number of antennas, for extraordinary broadband signal processing, for maintaining a satisfactory coverage and for tracking mobile devices with super-narrow beams. Therefore, reducing energy consumption and jointly coordinating distributed infrastructure to achieve net-work-wide optimal energy-efficiency constitute the first challenge in future 6G.