Fundamental Green Tradeoffs: Progresses, Challenges, and Impacts on 5G Networks

TLDR

Green radio is increasingly important for reducing operational costs and supporting sustainable wireless communications amid rapid traffic and energy growth, and its analysis is framed by fundamental tradeoffs such as spectrum‑efficiency versus energy‑efficiency, deployment‑efficiency versus energy‑efficiency, delay versus power, and bandwidth versus power. This paper aims to comprehensively review ongoing research efforts categorized by these fundamental green tradeoffs, focusing on 4G/5G advances in OFDM, NOA, MIMO, and HetNets, and to discuss challenges and impacts to guide future energy‑efficient network design. The authors categorize and analyze existing research by the four key tradeoffs, survey progress in 4G/5G technologies, and evaluate potential challenges and impacts to inform future energy‑efficient wireless network development.

Abstract

With years of tremendous traffic and energy consumption growth, green radio has been valued not only for theoretical research interests but also for the operational expenditure reduction and the sustainable development of wireless communications. Fundamental green tradeoffs, served as an important framework for analysis, include four basic relationships: spectrum efficiency (SE) versus energy efficiency (EE), deployment efficiency (DE) versus energy efficiency (EE), delay (DL) versus power (PW), and bandwidth (BW) versus power (PW). In this paper, we first provide a comprehensive overview on the extensive on-going research efforts and categorize them based on the fundamental green tradeoffs. We will then focus on research progresses of 4G and 5G communications, such as orthogonal frequency division multiplexing (OFDM) and non-orthogonal aggregation (NOA), multiple input multiple output (MIMO), and heterogeneous networks (HetNets). We will also discuss potential challenges and impacts of fundamental green tradeoffs, to shed some light on the energy efficient research and design for future wireless networks.