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Small-Net vs. Relays in a Heterogeneous Low Energy LTE Architecture

Weisi Guo and Tim O’Farrell
Department of Electronic and Electrical Engineering, University of Sheffield, United Kingdom

Abstract— The paper analyzes the energy consumption impact of introducing heterogeneous elements to a homogeneous deployment. Two contrasting low energy heterogeneous architectures are investigated: small cells (Small-Nets) and wireless relays. The investigation employs a multi-cell multi-user dynamic LTE simulator and both deployments are investigated for a range of urban traffic loads. The paper shows that compared to a homogeneous baseline deployment of micro-cells, both deployments reduce the total radio network energy consumption significantly (50 to 60%). The Small-Net approach reduces energy consumption by deploying more low power cells with a macro-overlay and achieves increased network capacity by spectrum reuse. The relaying approach reduces energy consumption by deploying fewer macro-cells and increases network capacity through increasing cell-edge performance.
A combination of deployment factors were investigated in order to find the lowest energy architecture within the heterogeneous deployments. For a range of targeted traffic loads, it was found that the lowest energy solution depends on the percentage of high mobility traffic. If the percentage of high-mobility users is below 8%, the Small-Net architecture is the lowest energy architecture. Otherwise, the wireless cell-edge relaying concept offers a greater energy reduction. The paper also presents theoretical upper-bounds on energy reduction for a fixed and changing deployment.

Index Terms— cellular network, heterogeneous, energy effi¬ciency, architecture, simulation

Cite:Weisi Guo and Tim O'Farrell, "Small-Net vs. Relays in a Heterogeneous Low Energy LTE Architecture ," Journal of Communications, vol. 7, no.10, pp.716-725, 2012. Doi: 10.4304/jcm.7.10.716-725