Ultra-Dense Networks for 5G and Beyond

11Simultaneous Wireless Information and Power Transfer in UDNs with Caching Architecture

Sumit Gautam, Thang X. Vu Symeon Chatzinotas and Björn Ottersten

Interdisciplinary Centre for Security, Reliability and Trust, University of Luxembourg, Luxembourg

11.1 Introduction

The exponential increase in the usage of wireless devices like smart‐phones, wearable gadgets, or connected vehicles has not only posed substantial challenges to meet the performance and capacity demands [1], but also revealed some serious environmental concerns with alarming energy consumption and CO₂ emissions [2]. These concerns become more significant as the forecast number of devices will exceed 50 billions by the end of 2020 [3]. Recent developments in the upcoming paradigm of Internet‐of‐Things (IoT) emphasize the interconnection between equipments, commodities, functionalities, and customers, with or without human mediation. Since most of these connecting operations involve wireless sensor nodes or equivalent battery‐limited devices that may not be continuously powered, energy becomes a sparse and pivotal resource. These challenges require the future communication networks to have not only efficient energy management but also the capability of being self‐powered from redundant energy sources, which is known as energy harvesting (EH).

Among potential EH techniques, simultaneous wireless information and power transfer (SWIPT) has received much attention as the key enabling technique for future IoT networks. ...