Energy-Efficient Ultra-Dense 5G Networks: Recent Advances, Taxonomy and Future Research Directions

Abstract

The global surge of connected devices and multimedia services necessitates increased capacity and coverage of communication networks. One approach to address the unprecedented rise in capacity and coverage requirement is deploying several small cells to create ultra-dense networks. This, however, exacerbates problems with energy consumption and network management due to the density and unplanned nature of the deployment. This review discusses various approaches to solving energy efficiency problems in ultra-dense networks, ranging from deployment to optimisation. Based on the review, we propose a taxonomy, summarise key findings, and discuss operational and implementation details of past research contributions. In particular, we focus on popular approaches such as machine learning, game theory, stochastic and heuristic techniques in the ultra-dense network from an energy perspective due to their promise in addressing the issue in future networks. Furthermore, we identify several challenges for improving energy efficiency in an ultra-dense network. Finally, future research directions are outlined for improving energy efficiency in ultra-dense networks in 5G and beyond 5G networks.

Optimizing energy efficiency in heterogeneous networks: An integrated stochastic geometry approach with novel sleep mode strategies and QoS framework

“…In the past few years, based on the observations presented in Table 1 . we see that extensive research has been carried out in the field of HetNets and its energy efficiency improvements [ 8 , 16 – 18 , 31 , 32 , 34 , 46 – 58 ]. A comprehensive literature review in the area of 5G-networks reveals that existing network models and algorithms aiming at providing energy solutions are still lacking in the precise solution of EE HetNets.…”

Joint Optimization of Bandwidth and Power Allocation in Uplink Systems with Deep Reinforcement Learning

“…The densification of the network [ 5 ] is one of the key features of the 5G wireless network architecture, which not only contributes to increasing the system capacity of 5G networks, but also is closely related to user experience enhancement. As an important technique for improving the efficiency and quality of communications, dense networks still suffer from extremely complex interference problems [ 6 ]. In the dense multi-cell multi-user system, explosive rising users in different cells have an interplay due to the reuse of resources, which leads to increased co-channel interference and scarce resources.…”

Capacity and Energy Efficiency Trade-off in Multi-Packet Reception Wireless Systems

“…The authors in [10] have developed a model capturing the effect of PHY layer parameters to analyze energy-efficient communications. In ultra-dense Networks (UDNs), there has also been a growing effort on optimizing the energy consumption [11]- [15]. The authors in [11] have discussed various approaches to handle energy efficiency problems in UDNs, ranging from deployment to optimization.…”

“…In ultra-dense Networks (UDNs), there has also been a growing effort on optimizing the energy consumption [11]- [15]. The authors in [11] have discussed various approaches to handle energy efficiency problems in UDNs, ranging from deployment to optimization. In [12], the authors have derived the ergodic capacity of the uplink UDN.…”