Collaborative Research: SII-NRDZ: ARA-NRDZ: From Site and Application Investigation to Prototyping and Field Testing

This research team will conduct preliminary studies leading to field trials of electromagnetic (radio-frequency) spectrum sharing at the ARA wireless living lab for rural broadband, which is sponsored by the NSF Platforms for Advanced Wireless Research (PAWR) program. Located in Central Iowa, ARA enables experimentation with novel spectrum sharing methods appropriate for rural areas. Rural areas have unique spectrum usage patterns, propagation characteristics, critical applications, and community needs, so spectrum sharing solutions for rural areas may differ from those appropriate for urban or suburban areas. The field trials enabled by this project will provide lessons learned that help improve real-world spectrum use efficiency, reduce spectrum access cost, and empower rural communities to participate in addressing the rural broadband challenge. This project will also create research opportunities for undergraduate and graduate students, as well as K-12 outreach. The initial application considered for potential field trials is spectrum sharing to enhance the Control and Non-Payload Communications (CNPC) and sensing functions of unmanned aircraft systems (UAS). UAS operations, especially beyond visual line of sight operations that depend on reliable spectrum access, are envisioned as a high-payoff capability supporting economic growth and public safety in rural areas. UAS CNPC is limited to a small, reserved band today because of the high reliability requirements for the service, while UAS sensing faces the same spectrum access challenges as all other sensing systems. Two sharing opportunities are initially of interest: achieving high reliability UAS CNPC in non-CNPC-reserved bands where other users also employ controlled, high-reliability communications, such as connected agricultural robots; and adding UAS sensing activities into the reserved UAS CNPC band in ways that preserve CNPC capacity and reliability. Success in these types of spectrum sharing will reduce the cost of delivering important UAS capabilities. Technical studies on ways to extended current ARA capabilities to support future spectrum sharing field trials include: adoption of software-defined radios; use of programmable commercial-off-the-shelf wireless systems; and support for bring-your-own-device experiments, enabling operation at frequency bands not accessible with the installed ARA hardware. Propagation measurements in the project will generate real-world measurements of wireless channels in rural regions. These data are essential for development of effective spectrum sharing methods. The project team will openly share results and actively collaborate with the broader SII-NRDZ community, to help define and realize the National Radio Dynamic Zones vision. 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.