Optimal Energy Management Policies for Energy Harvesting Sensor Nodes

TL;DR

This paper develops and compares energy management policies for energy harvesting sensor nodes, optimizing throughput and delay, and identifies a simple greedy policy effective in low SNR conditions.

Contribution

It introduces throughput optimal and delay-minimizing policies for energy harvesting sensors, including a simple greedy policy effective in low SNR regimes.

Findings

The proposed policies ensure queue stability at maximum data rates.

The greedy policy is throughput optimal in low SNR conditions.

The greedy policy also minimizes mean delay in low SNR regimes.

Abstract

We study a sensor node with an energy harvesting source. The generated energy can be stored in a buffer. The sensor node periodically senses a random field and generates a packet. These packets are stored in a queue and transmitted using the energy available at that time. We obtain energy management policies that are throughput optimal, i.e., the data queue stays stable for the largest possible data rate. Next we obtain energy management policies which minimize the mean delay in the queue.We also compare performance of several easily implementable sub-optimal energy management policies. A greedy policy is identified which, in low SNR regime, is throughput optimal and also minimizes mean delay.