Researchers in Spain are presenting a step toward more sustainable power for wireless communications systems as well as Internet of Things (IoT) devices.
Developed by a team from IMDEA Networks Institute in Madrid (in collaboration with Uppsala University in Sweden), a new system—PassiveLiFi—uses light fidelity (LiFi)—a wireless communication technology that uses light to transmit data between devices—to transmit radiofrequency (RF) backscatter—a passive and low-energy transmission technique—“at a meager power budget.” The system is completely battery-free.
“Our work opens the door to long-range, battery-free Internet of Things applications [including] retrofitting lighting infrastructure for communication,” says Dr. Domenico Giustiniano, a research associate professor at IMDEA, where he leads the Pervasive Wireless System Group. “[This is] something that was not previously possible to achieve.”
Limitation hurdles
Traditionally, ambient RF backscatter, which uses “an incident radiofrequency signal to transmit data without a battery or power source,” comes with limitations and challenges, including a lack of control over RF power levels (as there is no internal RF source). And because the backscatter can collect just a small amount of electricity, it can only be utilized for a few devices and components. Also, ambient backscatter technology faces “severe security issues” due to dependency on external RF signals. Additionally, RF backscattering touts low data rates as well as a lower coverage range.
The researchers cite, too, an urgent need “to find a solution for removing batteries without affecting communication performance and IoT services,” as batteries and their chemical components “threaten to have a huge environmental impact on the Earth.”
The IMDEA team has shown that LiFi can solve those limitations. The study has essentially demonstrated that “power-constrained IoT devices can reach very long-range transmission without affecting their power consumption.”
“Our solution solves the trade-off between the captured energy required by the IoT device and the desired data rate, allowing our system to operate without using batteries,” says Borja Genovés Guzmán, a post-doctoral researcher at IMDEA and a co-author of the study. He adds that this research shows that light sources “can be used efficiently and simultaneously as both a source of power harvesting and as a communications receiver.”
With the new LiFi/RF backscatter combination paving the way for battery-free communication, it could lead to a number of IoT applications, including smart homes, smart cities, and smart agriculture.
Justine Murphy | Multimedia Director, Digital Infrastructure
Justine Murphy is the multimedia director for Endeavor Business Media's Digital Infrastructure Group. She is a multiple award-winning writer and editor with more 20 years of experience in newspaper publishing as well as public relations, marketing, and communications. For nearly 10 years, she has covered all facets of the optics and photonics industry as an editor, writer, web news anchor, and podcast host for an internationally reaching magazine publishing company. Her work has earned accolades from the New England Press Association as well as the SIIA/Jesse H. Neal Awards. She received a B.A. from the Massachusetts College of Liberal Arts.