Adaptive Spectrum Sharing and UsE (ASSURE)

The Adaptive Spectrum Sharing and UsE (ASSURE) project investigates a new method for cellular (5G/6G) and radar systems to share a spectrum band, and it explores a general architecture for fine-grained spectrum sharing. The increasing use of wireless systems of all types is creating congestion in the limited available radio spectrum. The congestion can be reduced through sharing between services that previously required exclusive allocations. One example is the 2.7-3.1 GHz band used by federal radar systems. The radars in this band include airport surveillance radars and weather radars. Previously deployed radar-communications spectrum sharing approaches require shutting down the communications system when a radar is in interference distance. Since airports and weather radars are scattered widely across the US, use of such a sharing approach in the 2.7-3.1 GHz band would greatly limit cellular operations. The ASSURE project investigates different spectrum sharing approaches, in which the communications system operates safely within interference range of the radar by controlling transmission frequencies and times in a fine-grained manner to avoid the radar beam. If successful, the project will help advance the US as a leader in current, emerging and future spectrum use and wireless systems. The ASSURE project includes multiple research tasks. (1) Design and develop server software called Spectral Intelligence & Control (SIC) that transforms incoming information about users of a spectrum band into orchestration and control plans enabling safe fine-grained spectrum sharing. (2) Develop new site-specific and transceiver-specific interference models, expressed in IEEE spectrum consumption model format, for analysis of sharing opportunities. (3) Create OpenRAN rApp and xApp software modules for 5G cellular systems to interface to the SIC and control fine-grained spectrum sharing. (4) Develop radar operational mode detection methods based on spectrum sensors, for use when the radar operator does not share the information directly. (5) Develop monitor nodes to place near radar antennas to detect interference from cellular operations. (6) Use the building blocks from the previous tasks to implement sharing between 5G cellular and NEXRAD weather radars, running experiments using the University of Utah POWDER testbed. If experimentation in the 2.7 GHz band is not feasible, time-synchronized real-time sensing of a nearby NEXRAD radar (KMTX) together with over-the-air 5G experiments at 3.3 GHz will be performed, and then post-processed to evaluate whether interference would have occurred if both had been operating in the same band. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.