Medium Access Control Protocols for Wireless Sensor Networks with Energy Harvesting

TL;DR

This paper analyzes and designs MAC protocols for energy-harvesting wireless sensor networks, introducing a new delivery probability metric and exploring the trade-offs between delivery success and data collection rate.

Contribution

It provides a novel analytical framework for MAC protocols in EH-WSNs, incorporating a new delivery probability metric and examining performance trade-offs.

Findings

Delivery probability is crucial for EH-WSNs performance.

Trade-offs exist between delivery efficiency and data rate.

Analytical models validate the importance of considering both metrics.

Abstract

The design of Medium Access Control (MAC) protocols for wireless sensor networks (WSNs) has been conventionally tackled by assuming battery-powered devices and by adopting the network lifetime as the main performance criterion. While WSNs operated by energy-harvesting (EH) devices are not limited by network lifetime, they pose new design challenges due to the uncertain amount of harvestable energy. Novel design criteria are thus required to capture the trade-offs between the potentially infinite network lifetime and the uncertain energy availability. This paper addresses the analysis and design of WSNs with EH devices by focusing on conventional MAC protocols, namely TDMA, Framed-ALOHA (FA) and Dynamic-FA (DFA), and by accounting for the performance trade-offs and design issues arising due to EH. A novel metric, referred to as delivery probability, is introduced to measure the capability of a MAC protocol to deliver the measure of any sensor in the network to the intended destination (or fusion center, FC). The interplay between delivery efficiency and time efficiency (i.e., the data collection rate at the FC), is investigated analytically using Markov models. Numerical results validate the analysis and emphasize the critical importance of accounting for both delivery probability and time efficiency in the design of EH-WSNs.