Stefania Bartoletti is interested in where you are.
More precisely, the LIDS postdoctoral researcher, who works with Professor Moe Win’s research group, the Wireless Information and Network Sciences Laboratory, is interested in how to locate people and things in places where GPS doesn’t work well or is denied — in an environment such as a museum or shopping mall, for example, where the physical structure of the building inhibits the ability of a wireless device to connect with GPS satellites.
Having an accurate estimation of where people and things are and of their pattern of movement has a multitude of uses, such as knowing which shops or exhibits are most popular, or understanding which spaces within a building might need more energy for air-conditioning.
To capture this information, says Stefania, “You exchange some signals directly with the person or thing you’re trying to locate — that’s called active target. Otherwise, you emit a signal that is reflected off a person or an object and you try to understand where they are located based only on the reflections — that's called passive target.” Two examples of passive systems include anti-intruder alarm systems, which read the signals that bounce off an intruder to detect its presence, and radar systems, which read the signals that bounce off vehicles and drones to track their positions.
Stefania adds that while Professor Win’s group focuses on the theory and fundamental limits of active systems, she is adapting that research to study passive systems: How accurate can one be in an environment with passive systems? How much information can you extract from the signal you receive? She also seeks to understand which technologies are most suitable for passive systems. How might so-called ‘signals of opportunity,’ such as Wi-Fi or cellular signals already present for other uses, be exploited for location sensing?
Stefania is pursuing her research within the PATH project (PATH stands for PAssive Tracking of people and things for physical beHavior analysis) supported by a three-year Marie-Sklodowska Curie Fellowship from the European Commission, which runs through 2019. In addition to being a crucial paradigm for applications like crowd counting and flow monitoring, passive tracking also has implications for the Internet-of-Things, where this capability can be integrated into its infrastructure, making systems more versatile and accurate.
Professor Win notes the broad range of disciplines and methodologies involved in Stefania’s work, “Her project embraces communication theory, information theory, signal processing, statistical inference, and optimization, and it spans from the development of theoretical foundations to network experimentation via off-the-shelf radios. Stefania has a particular aptitude for translating her developed theories into practical systems — she’s a terrific collaborator.”
Stefania originally hails from the sundrenched town of Cosenza in Calabria, at the instep of Italy’s ‘boot,’ and calls herself the black sheep in a family of medical doctors. However, it was her parents who encouraged her interest in mathematics, teaching her to sketch out math problems as a way of tackling them. At eighteen, she left for university in Ferrara, a college town near Bologna in the north.
“I studied what’s called information engineering – it’s a degree that encompasses computer science and electrical engineering. Learning about wireless communication was the first time I had seen many mathematical theories applied,” Stefania says. “I think wireless communication is one of the most interesting combinations of mathematics and statistics. When you receive a signal, you have to understand what was transmitted and it’s all based on probability and inference; you see all kinds of mathematical and statistical tools applied at different points.”
Learning about radar, too, was a revelation. “I learned that some planes have a layer of paint that makes them invisible to radar. That’s how I became interested in radar – it was the first time I had seen something ‘invisible’ that was a real thing,” Stefania laughs.
At the University of Ferrara, she studied with Professor Andrea Conti, a long-standing close collaborator of Professor Win and Research Affiliate at LIDS. It was he who suggested she look into MIT and LIDS, where Professor Win is an expert on the communications technologies she was interested in. “Stefania is a passionate and committed researcher,” says Professor Conti. “She has great potential — and I knew LIDS could be an excellent fit for her.” Professor Conti was not the only one to recognize Stefania’s potential. In 2016 she was named one of four Marconi Society Young Scholars, an award that recognizes young scientists and engineers around the world for their potential in communications and information technology.
Arriving in Cambridge, Stefania was astonished by MIT’s size and LIDS’ international, interdisciplinary culture. “Ferrara is a small city – the city center is smaller than the MIT campus,” she says. “And LIDS is my first experience with truly interdisciplinary activities. Everyone’s interested in what you do, and you work on different things but share ideas with each other. It’s amazing to go to all these seminars and tea talks; I think the future of science is interdisciplinary.”
Here, too, she feels more equipped with the mathematical, statistical, and experimental tools to apply localization technology to understanding people’s movement and behavior. She and her colleagues use sensor systems to test different algorithms, different sensor configurations, and how best to remove background noise and clutter to identify targets more clearly.
But LIDS doesn’t just equip scholars with a strong technical foundation, Stefania says. “MIT has a very good technology licensing office and they help you with a lot” – such as writing a patent and understanding what is patentable and what isn’t.
Stefania is conducting her PATH project research between both LIDS and the University of Ferrara. As part of her fellowship, she also plans to gain experience in industry before continuing with research, whether in a research institution or in corporate research and development. “I’d like to broaden my horizons in terms of the topics I study, too,” she adds.
Meanwhile, she keeps busy, picking up the guitar and serving on the board of MITaly, the campus Italian association. Whether for work or for leisure, she’s also traveled quite a bit: to Utah and Arizona, Florida, New York, Seattle and even Australia. “I never thought I’d go to the US or travel so much,” she marvels.
Her work and travels may have taken her far beyond the coasts of Southern Italy, but fittingly, it is clear that Stefania knows where she is, and where she is going.