Rui Zhang, assistant professor of computer science at the University of Delaware, has received a prestigious National Science Foundation Faculty Early Career Development Award, “Secure Database-Driven Dynamic Spectrum Sharing,” to address issues of security and privacy surrounding radio spectrum sharing.

The five-year, $500,000 grant was awarded through NSF’s Division of Computer and Network Systems.

Zhang explains that in 2012, President Barack Obama’s top technology advisers recommended that the federal government share its underused radio spectrum to help service providers meet increasing demand.

“The explosion of new apps for smartphones and tablets, as well as increased use of these devices for watching videos, has brought about exponential growth in wireless data traffic,” Zhang says.

“The 2012 recommendation was aimed at taking advantage of the radio frequencies that are allocated to licensed users but underused — either because there is insufficient demand from licensed users or because the frequencies have been freed up by technology changes such as the switch from analog to digital TV.”

One solution to managing the sharing of this resource is an approach called database-driven dynamic spectrum sharing, or DSS, in which a geo-location database accepts registrations from licensed users, determines spectrum availability, and then responds to queries from unlicensed users who are interested in using a certain spectrum band.

However, the mechanisms used to protect licensed users from interference in this shared space are very conservative, resulting in wasted spectrum opportunities.

To address this problem, the Federal Communications Commission (FCC) recommended the use of sensors to determine whether licensed users were actually sending signals at any given time or location. Because the deployment of a dedicated sensor system is prohibitively expensive, it was proposed that the required sensing capability be crowd-sourced through the millions of mobile devices already in use.

While this proposal was economically sound, it brought with it a new set of problems revolving around fundamental issues of security and privacy.

Zhang’s NSF-supported research will address three challenges connected with these issues.

The first is to ensure that a robust map of available spectra can be developed even if some of the field measurements collected by mobile users are inaccurate. Second, he and his team will develop incentive mechanisms to stimulate mobile users to participate in spectrum sensing while protecting their privacy. And, finally, they will create spectrum misuse detection techniques to ensure that the available radio spectrum is used only by authorized unlicensed users.

“Our hope is that this research will accelerate the opening up of underutilized licensed spectra for sharing and pave the way for widespread development and deployment of database-driven dynamic spectrum sharing systems,” Zhang says. “The work will also enrich scientific knowledge about network and distributed system security and wireless networking.”

About the professor

Rui Zhang earned bachelor’s and master’s degrees, in 2001 and 2005, respectively, from Huazhong University of Science and Technology, China, and his doctoral degree in electrical engineering from Arizona State University in 2013.

He joined the University of Delaware faculty in 2016 after serving as an assistant professor in the Department of Electrical Engineering at the University of Hawaii from 2013 to 2016. Previously, he spent two years as a software engineer at UTStarcom in Shenzhen, China.