Optimal Control of Wake Up Mechanisms of Femtocells in Heterogeneous Networks

TLDR

The study seeks to minimize energy consumption of heterogeneous networks by optimizing sleep/wake‑up schemes for femto base stations deployed within macro cells, while preserving user QoS. The authors model the system at flow level, use Markov Decision Processes to derive optimal sleep/wake‑up policies based on traffic load and user location under complete, partial, or delayed information, and illustrate the resulting policies numerically across traffic scenarios. The results quantify energy consumption and QoS perceived by users in each case and identify tradeoffs between these two quantities.

Abstract

We study, in this work, optimal sleep/wake up schemes for the base stations of network-operated femto cells deployed within macro cells for the purpose of offloading part of its traffic. Our aim is to minimize the energy consumption of the overall heterogeneous network while preserving the Quality of Service (QoS) experienced by users. We model such a system at the flow level, considering a dynamic user configuration, and derive, using Markov Decision Processes (MDPs), optimal sleep/wake up schemes based on the information on traffic load and user localization in the cell, in the cases where this information is complete, partial or delayed. Our results quantify the energy consumption and QoS perceived by the users in each of these cases and identify the tradeoffs between those two quantities. We also illustrate numerically the optimal policies in different traffic scenarios.