Radio frequency (RF) spectrum has become a scarce resource. The days of exclusive spectrum allocations are gone – the age of spectrum sharing is upon us. Sharing between systems that transmit – active systems – can be performed using variations of a “listen before talking†protocol that checks whether a particular RF frequency band is being actively used and only transmits if the frequency band is unused. Passive systems, such as radio telescopes and earth observation satellites, do not transmit. Sharing between passive and active systems is therefore particularly challenging, because sensors cannot determine if a passive system is in use. Consequently, passive-active sharing is static, not dynamic, and performed by defining RF quiet zones around passive systems. Additionally, many passive systems are sensitive to RF noise pollution, which may result from leakage from unshielded devices, or the aggregation of faint signals from a multitude of devices. However, little work has been done on systematically surveying RF noise to understand where noise is increasing, the extent of the increase, and the changes over time. The proposed Passive and Active Spectrum Sharing (PASS) project will systematically survey and characterize RF noise, and explore and evaluate alternatives for enabling spectrum sharing between passive and active systems. The PASS research will be a significant step forward in understanding and mitigating RF noise, and will enable more dynamic and efficient sharing of spectrum.
The proposed Passive and Active Spectrum Sharing (PASS) project will: (i) systematically survey RF noise across multiple environments; (ii) analyze and characterize RF noise and evaluate mechanisms to mitigate noise; (iii) explore new and innovative approaches to dynamic spectrum sharing between passive and active systems; (iv) analyze and quantitatively evaluate mechanisms to coordinate bi-directional spectrum sharing between passive and active systems; (v) explore hardware and software approaches to enhance the effectiveness and security of spectrum sharing; and (vi) define the requirements and initial processes to maintain a National Radio Dynamic Zone (NRDZ), a geographic region within which bi-lateral spectrum sharing takes place. The results from this project will provide experimental and analytical evidence on RF noise control and spectrum sharing; enable more effective dynamic utilization of spectrum, and inform the creation of an NRDZ. Further, the project will develop data structures, processes, and software to enable future multi-institutional collaboration on RF noise measurement and modeling.
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.
