Wireless technology has advanced dramatically in the past 20 years, and wireless networks have been expanding nonstop. However, this expansion has caused a growing problem: too many systems competing for finite spectrum.
At the Idaho National Laboratory (INL), Arupjyoti “Arup” Bhuyan has spent years working on a solution. His new patent for autonomous beam scheduling enables secure 5G spectrum sharing, helping multiple networks use that space efficiently — without slowing each other down. His patented spectrum-sharing algorithm could help power private 5G networks for applications ranging from smart factories and warehouses to emergency response.
A remote beginning with a clear path
The road to that breakthrough began far from Idaho.
Bhuyan grew up in Assam, a somewhat remote state in northeastern India. It sits near the foothills of the Himalayas and is known for its tea gardens, lush forests and a fertile river valley. He arrived in America with no relatives and no road map.
“Where I grew up, what I could think about and achieve was limited by the environment around me,” said Bhuyan, now a National and Homeland Security directorate fellow at INL.
In Assam, the path for a smart kid ran one of two directions: medicine or engineering. Bhuyan chose engineering early on, drawn in by a love of math and repelled by the memory of dissecting frogs in school. He earned a spot at the Indian Institute of Science in Bangalore — one of the nation’s most prestigious institutions of higher learning — where professors who conducted collaborative research with universities in the United States opened a window onto a world he had never imagined.
“My advisor told me that if I wanted to do cutting-edge research, I should go to the U.S.,” Bhuyan said.
After earning his undergraduate degree from the Indian Institute of Science, Bhuyan took that advice straight to Yale University. He arrived in New Haven, Connecticut, in the mid-1980s. It was his first time leaving India.
The culture shock was immediate. The campus layout felt different, food was unfamiliar and the surprising informality between students and professors was strange. The cumulative effect of so many little adjustments was overwhelming.
But the deeper disruption was intellectual — and ultimately transformative.
“The challenge of independent thinking to tackle unsolved problems — that really was what changed everything,” Bhuyan said. “In India, I grew up solving problems with known solutions in textbooks. Here, being a graduate student, I had to come up with innovative solutions with limited guidance. You have to mostly rely on your own thinking.”
That shift toward independent thinking would shape the rest of his career.
Bhuyan earned both a master’s degree and a Ph.D. in electrical engineering from Yale, winning the Yale University Fellowship and the Thomas Alva Edison Fellowship along the way. He then spent more than two decades at Bell Labs and its successor organizations, working on telecommunications systems and earning multiple patents in wireless content delivery.
“Ever since I started doing research, I wanted to invent.” Bhuyan said.
Deeper researcher, bigger impact
As industry priorities shifted, he wanted to return to deeper research. That opportunity came when an INL recruiter found his LinkedIn profile in 2015. At INL, he found a different kind of environment, one that was focused on long-term research and national challenges.
What sold Bhuyan on INL was its ability to run its own at-scale wireless network and push it to the point of failure with simulated adversarial attacks to find and fix vulnerabilities. INL’s wireless communications research infrastructure — including the ability to operate standards-compliant 2G, 3G, 4G and 5G networks, and other capabilities — gave him the tools to pursue advanced applied research at a national scale.
“The best part of working here is solving problems that are relevant to the national security,” Bhuyan said.
Bhuyan conducted several Lab Directed Research and Development (LDRD) projects. INL’s LDRD program empowers high-risk, high-reward research that positions the laboratory to respond quicky to evolving national energy and security challenges.
He then turned his attention to another challenging wireless communications problem: how to let multiple, private 5G networks share the same spectrum without knocking each other offline.
Solving a growing wireless problem
As 5G technology expands, so does demand for wireless spectrum, the radio frequencies that carry wireless data from one location to another. Today, sharing that spectrum often relies on centralized systems that control who can transmit and when. But that approach can slow things down as more networks compete for access.
To understand Bhuyan’s patented solution, imagine a meeting with hundreds of participants who each need the spotlight. If every participant speaks at once, their messages will drown in unintelligible chatter. That’s why a host needs to watch the room and decide who gets to speak. It keeps information from disintegrating into meaningless noise, but it also creates additional delays.
Likewise, using the wireless shared spectrum requires a host to coordinate the users. That host is called a spectrum access server. Just as a meeting host creates a bottleneck as everyone waits for the host to assess the room, pick a speaker and hand off the mic, the spectrum access server creates bottlenecks as it coordinates users for limited spectrum. The more participants, the worse the delay. This central coordinator is also a strategic target for adversarial attacks — no one can speak if you take out the host.
Bhuyan’s patented solution removes that bottleneck and protects against attacks.
Imagine if, instead of a meeting that relies on a central host to coordinate speakers, everyone had a headset that knew when to automatically turn on microphones at the right moment. It would eliminate the need for a centralized decision-maker that causes bottlenecks.
Likewise, instead of relying on a central controller, Bhuyan’s approach uses a distributed algorithm that allows base network stations to coordinate access on their own.
“The technology gap we currently have is how do you effectively share the spectrum with autonomous and distributed decisions made at the 5G base station without colliding with each other,” Bhuyan said.
Bhuyan’s autonomous beam scheduling algorithm is built on a mathematical framework called Lyapunov stochastic optimization and is informed by game theory, the study of strategic decision-making. The algorithm allows multiple networks sharing the same spectrum to transmit in coordinated turns — independently, securely and without any central coordinator.
“In particular, I like the distinction between centralized and distributed control,” Bhuyan said. “That is very powerful.”
Bhuyan collaborated with researchers at the University of Utah, whose mathematical expertise helped accelerate the work.
“When you start collaborating, things just take shape — it’s a beautiful thing,” he said.
By solving the centralization problem, the technology could increase wireless capacity and speed; facilitate private 5G networks for industry and government; support industrial Internet of Things, the wireless technology that enables smart homes, wearable technology and other connected devices used in smart manufacturing and emergency response; and reduce reliance on expensive licensed spectrum use like the kind provided by cellphone carriers. The automated scheduling of private 5G networks could shape the future of wireless communication.
A broader mission
For Bhuyan, who journeyed from the tea gardens of Assam to the high deserts of eastern Idaho, INL work carries personal weight. He recently performed a 5G security assessment for the Office of the Under Secretary of War for Research and Engineering, where he demonstrated real-world wireless vulnerabilities to Department of War officials who had never seen anything like it.
“I really like solving problems that are of national interest,” he said. “I feel like I’m making a difference.”
With more than 80 peer-reviewed publications, eight issued patents and another one pending, Bhuyan has made a difference and shows no signs of slowing down. The Rocky Mountains outside his Idaho Falls, Idaho, office window, not unlike the Himalayas he glimpsed as a child, remain a reminder of how far curiosity can carry a person — and the world.
Learn more about INL’s wireless communications research here.
