On Maximizing Energy and Spectral Efficiencies Using Small Cells in 5G and Beyond Networks

Abstract

Addressing high capacity at low power as a key design goal envisages achieving high spectral efficiency (SE) and energy efficiency (EE) for the next-generation mobile networks. Because most data are generated in indoor environments, an ultra-dense deployment of small cells (SCs), particularly within multistory buildings in urban areas, is revealed as an effective technique to improve SE and EE by numerous studies. In this paper, we present a framework exploiting the four most interconnected-domain, including, power, time, frequency, and space, in the perspectives of SE and EE. Unlike existing literature, the framework takes advantage of higher degrees of freedom to maximize SE and EE using in-building SCs for 5G and beyond mobile networks. We derive average capacity, SE, and EE metrics, along with defining the condition for optimality of SE and EE and developing an algorithm for the framework. An extensive system-level evaluation is performed to show the impact of each domain on SE and EE. It is shown that employing multiband enabled SC base stations (SBSs) to increase operating spectrum in frequency-domain, reusing spectrum to SBSs more than once per building in spatial-domain, switching on and off each in-building SBS based on traffic availability to reduce SBS power consumption in power-domain, and using eICIC to avoid co-channel interference due to sharing spectrum with SBSs in time-domain can achieve massive SE and EE. Finally, we show that the proposed framework can satisfy SE, EE, as well as user experience data rate requirements for 5G and beyond mobile networks.

Towards Sustainable 5G Networks: A Proposed Coordination Solution for Macro and Pico Cells to Optimize Energy Efficiency

“…One technique widely studied for optimizing energy consumption in radio access networks is the association between the base station (BS) and users. Previous studies have proposed various algorithms or methods of UE-BS association with the primary objective of load balancing, quality of service, spectral efficiency, and moderate energy efficiency [14], [15]. However, in heterogeneous networks, traditional association techniques such as Max-SINR or maximum achievable throughput, which rely mainly on the power received by the mobile, are no longer suitable due to the differences in transmission power between macrocells and small cells.…”

Millimeter-Wave Spectrum Utilization Improvement in Multi-Operator Networks: A Framework Using the Equal Likelihood Criterion

“…Moreover, in SD, the authors have exploited the SD within multistory buildings deployed with small cells of MNOs to reuse the allocated microwave spectrum in [29] and mmWave spectrum in [16], [30] to its indoor small cells more than once subject to satisfying a minimum interference limit set in prior by the MNO between co-channel small cells. Finally, in [35], the authors have exploited all four domains (i.e., TD, FD, PD, and SD) to present a theoretical framework, which has been detailed further in [36], for indoor small cells to achieve the prospective SE and EE requirements for 6G mobile networks.…”

“…The framework presented in this paper gives a general review of our findings, mostly in [4][5][6][7], [11][12][13][14][15][16], [29][30][31][32][33][34][35][36], and [40][44][52], relating to improving spectrum utilization of the 28 GHz mmWave systems using indoor small cells in multi-operator network scenarios for 5G and beyond mobile systems. In doing so, we use the Equal Likelihood Criterion and the properties of left-justified Pascal's triangle to derive closed-form solutions with a view to summarizing those findings in a unified manner for each spectrum allocation technique in each domain of the framework in terms of the system-level average capacity, SE, and EE performance metrics.…”

Exact analysis of maximal ratio transmission‐based decode‐and‐forward relaying with arbitrary number of co‐channel interferers

“…Moreover, the number of cells tends to increase in order to improve energy efficiency and reduce latency; thus, there will be more cells using the same bands due to the frequency reuse that increases capacity. 11,12 Consequently, the research on the influence of CCI has been increasing for both AF and DF relaying systems (e.g., previous studies [13][14][15][16][17][18][19][20][21][22] and references therein). For instance, Al-Qahtani et al 16 obtain only the outage probability (OP) for AF-OWRN with single antenna nodes over Nakagami-m channel with CCI at the relay and destination.…”

“…In the next‐generation networks, 10 CCI is expected to increase further since the number of users and devices in the same cluster is growing while frequency bands are limited. Moreover, the number of cells tends to increase in order to improve energy efficiency and reduce latency; thus, there will be more cells using the same bands due to the frequency reuse that increases capacity 11,12 . Consequently, the research on the influence of CCI has been increasing for both AF and DF relaying systems (e.g., previous studies 13–22 and references therein).…”