Proactive Push with Energy Harvesting Based Small Cells in Heterogeneous Networks

TL;DR

This paper develops an optimal push policy for energy harvesting small-cell base stations in heterogeneous networks, significantly improving service capability by leveraging battery energy, user requests, and content popularity.

Contribution

It formulates the push mechanism as a Markov decision process and proposes an algorithm to find the optimal policy with a state-dependent threshold structure.

Findings

Over 50% performance gain with the optimal push policy

Optimal policy adapts based on battery, request, and content states

State-dependent threshold structure identified

Abstract

Motivated by the recent development of energy harvesting communications, and the trend of multimedia contents caching and push at the access edge and user terminals, this paper considers how to design an effective push mechanism of energy harvesting powered small-cell base stations (SBSs) in heterogeneous networks. The problem is formulated as a Markov decision process by optimizing the push policy based on the battery energy, user request and content popularity state to maximize the service capability of SBSs. We extensively analyze the problem and propose an effective policy iteration algorithm to find the optimal policy. According to the numerical results, we find that the optimal policy reveals a state dependent threshold based structure. Besides, more than 50% performance gain is achieved by the optimal push policy compared with the non-push policy.