The SDR-Driven Crescendo Aims to Tame the Airwaves, Boost Bandwidth While Improving Security

By SDR News On Oct 28, 2023

Researchers at the University of California, San Diego have come up with a new approach to wireless communication that they say can improve both security and efficiency: Crescendo.

“Through careful analysis of spectrum usage, we can identify underutilized segments and hidden opportunities that, when exploited, would lead to a cost-effective connectivity solution for users around the world,” said Dinesh Bharadiya, senior author of the paper describing the Crescendo system . “Crescendo is at the forefront of this initiative, offering a low-complexity yet highly efficient solution with advanced algorithms that provides robust spectrum information for all.”

Raghav Subbaraman (pictured) and his colleagues hope to increase wireless bandwidth and security with a system they call Crescendo. (📷: Areli Alvarez/QI)

The idea behind Crescendo is simple enough: using adaptive software paired with software-defined radio (SDR) hardware, Crescendo scans the airwaves on broadband frequencies currently reserved for use by the military and other priority users — then maps when they’re sitting idle . Then, according to the team, these periods can be used by civilian communications systems – increasing the available bandwidth.

However, the same approach is said to improve the security of communication systems using the scanned frequencies: a system that can detect signal interference from nearby transmitters and reassign its own transmissions accordingly can also detect adversary attacks in real time. “Knowing what’s happening on the spectrum helps us improve communications, regulation, privacy and security,” says lead author Raghav Subbaraman.

The Crescendo architecture turns off-the-shelf SDR hardware into wideband spectrum sensors. (📷: Subaraman et al.)

A prototype built with off-the-shelf components, including a USRP X300 software-defined radio with a TwinRX daughterboard, showed the approach outperforming previous wideband spectrum sensors with a 30dB increase in dynamic range and a 10dB increase in signal-to-noise ratio (SNR).

The team’s work is published under open access conditions in Proceedings of the 29th Annual International Conference on Mobile Computing and Networking (ACM MobiCom ’23).