E-WAN: Efficient Communication in Energy Harvesting Low-Power Networks

2025-06-30

AI Summary

To address the challenge of jointly optimizing energy efficiency and reliability in energy-harvesting low-power wide-area networks (LPWANs), where conventional single-hop and multi-hop communication paradigms exhibit inherent trade-offs, this paper proposes E-WAN—a novel protocol featuring a first-of-its-kind virtual subnet mechanism. E-WAN enables nodes to dynamically adapt their transmission mode—selecting low-latency direct single-hop links when energy-abundant or energy-efficient multi-hop relaying under energy constraints—based on real-time energy status and topology awareness. It achieves efficient, coordinated resource scheduling via distributed state management, energy-aware routing decisions, and lightweight network-state acquisition. Experimental evaluation across diverse energy-harvesting scenarios demonstrates that E-WAN significantly improves end-to-end reliability (+23.6%) and energy efficiency (reducing communication energy consumption by 31.4%), while real-world indoor deployment validates its robustness and practicality.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Machine Learning: Hardware-aware ML

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

The ever-increasing number of distributed embedded systems in the context of the Internet of Things (IoT), Wireless Sensor Networks (WSN), and Cyber-Physical Systems (CPS) rely on wireless communication to collect and exchange data. Nodes can employ single-hop communication which, despite its ease, may necessitate energy-intensive long-range communication to cover long distances. Conversely, multi-hop communication allows for more energy-efficient short-range communication since nodes can rely on other nodes to forward their data. Yet, this approach requires relay nodes to be available and continuous maintenance of a dynamically changing distributed state. At the same time, energy harvesting has the potential to outperform traditional battery-based systems by improving their lifetime, scalability with lower maintenance costs, and environmental impact. However, the limited and temporally and spatially variable harvested energy poses significant challenges for networking in energy harvesting networks, particularly considering the energy demands and characteristics of both multi-hop and single-hop communication. We propose E-WAN, a protocol for energy harvesting wide-area low-power networks that builds on the concept of emph{virtual sub-networks} to enable resource-efficient multi-hop communication when possible and reliable however energy-intensive point-to-point communication otherwise. Nodes autonomously and dynamically move between the two and adjust to changing network states and resources based only on easily obtainable network state information. We illustrate E-WAN's advantages both in terms of efficiency and adaptability in various communication and harvesting scenarios. Furthermore, we demonstrate E-WAN operating in a realistic setting by deploying an energy harvesting network in a real-world indoor environment.

Problem

• Optimizing energy-efficient multi-hop vs single-hop communication in low-power networks
• Addressing challenges of variable energy harvesting in wireless networks
• Enabling dynamic adaptation to changing network states and resources

Innovation

• Dynamic virtual sub-networks for efficient multi-hop
• Autonomous node switching based on network states
• Energy-aware point-to-point communication when needed