Reaching a Compromise: The Complex Problem of Optimizing Large-Scale Wireless Networks
April 23, 2021
Researchers reveal a counterintuitive trade-off between optimizing low-power wide-area networks for energy, monetary, or environmental costs
Low-power wide-area networks (LPWANs) are being adopted for remote monitoring applications in many places, and they are getting increasingly larger in scale. However, as revealed in a recent study published in ETRI Journal, optimizing LPWANs solely in terms of energy use can actually be more expensive and environmentally damaging. Researchers developed a comprehensive theoretical framework and models to analyze the different costs of LPWANs, providing strategies to make smart compromises in different areas to achieve the best overall performance.
As mobile technology and the Internet of Things (IoT) keep evolving, new applications for the unprecedented network coverage are being intensely studied and evaluated. Low-power wide-area networks (LPWAN) are a peculiar type of architecture in which many wireless devices — usually sensors — are deployed over vast zones of interest to gather data remotely. As the name implies, the LPWAN architecture was designed with energy efficiency in mind because the devices served are expected to operate on batteries for extended durations and can result in a hazardous environmental waste from consumed batteries. However, as a recent study published in ETRI Journal revealed, optimizing LPWANs solely in terms of energy use may actually be worse from environmental and economic standpoints.
These somewhat counterintuitive findings were reported by a research team from Université de Lorraine, France. Noting the increasing scale of LPWANs, the team sought to establish a way to calculate their actual operational costs in a realistic setting, thereby addressing a knowledge gap in the literature. “Previous studies have only focused on the energy consumption of IoT and LPWAN end devices, but there are no generic metrics to report or optimize the actual costs of the network architecture,” explains Mina Rady, the study’s first author.
To tackle this problem, they first developed a theoretical framework for analyzing the cost of LPWANs in terms of their energy use, operational expenditure, and environmental footprint. Unlike previous works, their energy model considered the energy used by different sensing scenarios besides the energy required for transmission at the end devices. Meanwhile, the operational expenditure model included maintenanceand battery prices, battery charge capacities, battery replacement costs, and communication costs per bit transmitted. Finally, the environmental cost model dealt with the amount of solid waste generated by the use and replacement of Li-ion batteries at the end devices.
The team used this framework to develop a budget optimization model to determine the best assignment of links between end devices and gateways (service providers) according to any desired parameter. To test their approach, they conducted simulations of a realistic LPWAN using the actual locations of long-term evolution base stations in Paris as a guideline and by applying the LoRaWAN technology. Interestingly, the researchers found that there can be a serious trade-off between optimizing LPWANs for energy, operational, or environmental costs.
Thus, it is important for operators to consider LPWANs as part of large infrastructures with complex performance indicators that go beyond simply minimizing energy use. The team also showed how small compromises can be made in each direction to achieve a sort of global optimization with better overall performance. “We demonstrated multiple cases in which minor changes to the network configuration can result in great monetary and environmental savings, sometimes as high as thousands of euros and about half a kilogram of yearly chemical waste,” remarks Mr. Rady.
This study is a step in the direction to ensure the proper adoption of IoT and similar large-scale communication technologies. And it is also important to acquire a more comprehensive view of the problem at hand.
Reference
Titles of original paper: Can energy optimization lead to economic and environmental waste in LPWAN architectures?
Name of authors: Mina Rady, Jean-Philippe Georges, Francis Lepage
Affiliation: Université de Lorraine
About Mr. Mina Rady
Mina Rady obtained a Bachelor’s degree in computer science from The American University in Cairo in 2011. He then worked for two years as a research student at Massachusetts Institute of Technology, USA. In 2016, he joined the University of Lorraine, France, as part of a Master’s program in Pervasive Computing and Communications. He concluded his Master’s thesis in 2018 and is now a PhD candidate in the area of wireless industrial mesh networks.
Media contact:
Mr Mina Rady:
https://www.facebook.com/mianrady1
https://www.linkedin.com/in/minarady/
https://www.researchgate.net/profile/Mina-Rady
Professor Jean-Philippe Georges:
https://www.linkedin.com/in/jean-philippe-georges-49ba37b2/
