HCRO NRDZ: Hat Creek Radio Observatory National Radio Dynamic Zone

Project Overview:

Hat Creek Radio Observatory in Northern California
Spectrum sharing between passive and active systems has not been well researched. Deployed methods of spectrum sharing require some means of detecting whether a radio frequency (RF) band is being actively used. Passive systems do not transmit, so no means are available to detect over the air whether a passive system is operating. Currently, passive systems are protected by prohibiting all transmissions in specific frequency bands, requiring coordination with other services, or by designating geographic radio quiet zones (RQZs) within which transmissions are prohibited at all frequencies. However, increasing numbers of wireless devices are believed to be increasing the levels of ambient RF noise. Further, the increasing demand for spectrum is forcing more spectrum sharing between disparate radio services. New and innovative means are required to enable co-existence of passive and active services while making more spectrum available for the increasing number of active users. Additionally, to maximize the effectiveness of sharing and to protect the interests of both communities, the spectrum sharing mechanisms must be dynamic and secure, and must also address Personally Identifiable Information (PII) concerns.

Project Goals:

HCRO Field View.
The HCRO-NRDZ Prototype team will attack the challenges associated with generalized dynamic spectrum sharing within a National Radio Dynamic Zone with a systematic, collaborative approach that will both advance the state of the art in spectrum science, spectrum sharing, and spectrum security while demonstrating mechanisms to enable co-existence and more effectively utilize spectrum by dynamically sharing between passive and active services.

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Key activities of the HCRO-NRDZ Prototype proposal include:

  • HCRO environmental spectral assessment including identification and classification of various system types, or activities that generate the most significant interference.

  • A systematic survey of RF noise around the Hat Creek Radio Observatory.ÌýBaseline RF Noise Survey open data sets will be made available to the NRDZ research community.

  • Deployment of Google Spectrum Access System (SAS) at HCRO for RA spectrum protection and spectrum sharing.ÌýExtending the SAS framework to include satellite coordination will be investigated.

  • Exploration into new approaches and architectures for generalized spectrum sharing.

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The HCRO-NRDZ Prototype activites build upon the original NSF SWIFT University of Colorado Passive and Active Spectrum Sharing (NSF Award #2030233) key objectives:

  • Analysis and characterization of RF noise with respect to environmental parameters to identify patterns. The team will explore RF noise mitigation approaches based on results.

  • Exploration of new approaches to dynamic spectrum sharing between passive and active services.

  • Quantitative analysis of dynamic spectrum sharing mechanisms extended to enable sharing between passive and active services.

  • Exploration of approaches to optimize the efficiency and security of dynamic spectrum sharing.

  • Exploration of operational mechanisms for a National Radio Dynamic Zone (NRDZ).

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HCRO-NRDZ Prototype will make multiple contributions to the scientific community, including:

  • Tested, documented, and publicly accessible best practices for RF noise measurement.

  • Documented data and metadata formats for RF noise measurements, and open RF noise data sets to enable multi-institutional collaboration in measurement and analysis.

  • Tools and metrics for quantitative analysis of dynamic spectrum sharing effectiveness.

  • Processes for optimizing the effectiveness and security of dynamic spectrum sharing.

  • Preliminary operational definition and requirements for a NRDZ.

  • Increased spectrum coordination for protection of RA observations.

  • Lessons-learned for the general NRDZ research community.

This project addresses three primary intellectual challenges, as described below:

Systematic treatment of RF noise -ÌýRF noise is believed to be increasing due to the increasing prevalence of wireless devices, cellular communications, satellite communications, and more. Passive systems, such as radio astronomy (RA) observatories and Earth observation satellites have reported problems due to RF noise. Yet, no comprehensive, longitudinal studies of RF noise have been conducted. The HCRO-NRDZ project directly addresses this issue. The HCRO-NRDZ team will develop and refine processes to measure and monitor RF noise and will develop and refine data structures and databases for long-term storage and analysis of RF noise. A cloud-based architecture will be utilized to host a research community Open RF Data Set repository and provide tools for analytical purposes to encourage community-wide collaboration. HCRO-NRDZ will perform and publish a baseline RF noise survey that can be analyzed and built upon by a larger community. HCRO-NRDZ will enable collaborative measurement, analysis, and characterization of RF noise, and long-term analysis of noise trends.Ìý

Dynamic spectrum sharing between passive and active systems -ÌýMany instances of dynamic spectrum sharing exist, ranging from the local sharing between low power systems such as Wi-Fi and Bluetooth, to the more recent sharing between broadband services and radars. However, this is spectrum sharing between active services, and relies on sensing transmissions, which is not possible with passive systems such as radio telescopes. Yet, as spectrum becomes increasingly scarce, passive systems are likely to lose exclusive allocations and will be forced to share. Ideally, bi-lateral spectrum sharing would enable passive systems to gain access to more spectrum, if only for limited blocks of time. HCRO-NRDZ will survey dynamic sharing mechanisms and quantitatively evaluate applicability to dynamic, bi-lateral spectrum sharing. HCRO-NRDZ will enable a broader and more inclusive investigation of spectrum sharing. HCRO-NRDZ will further investigate the inclusion of earth RF transmitting satellites into a generalized automated spectrum sharing architecture.

Evolution towards the Definition of an NRDZ -ÌýAn NRDZ is effectively a geographic region within which bi-lateral spectrum sharing takes place. The research performed at the HCRO/SETI facility on bi-lateral spectrum sharing will enable preliminary definition of the requirements and operating procedures for the NRDZ community. There is an important need to integrate the manual policy and regulations process to support NRDZ stakeholders as a capability of the automated system – this is a challenge to be addressed.ÌýHCRO-NRDZ will lay the groundwork for further refinement and development of the NRDZ automated spectrum sharing concept.

The impact of the HCRO-NRDZ project will be felt in three primary domains: research and engineering, education and regulatory.Ìý

The research and engineering domain -ÌýHCRO-NRDZ will contribute data formats, datasets, analysis tools, and measurement survey processes to the greater community. RF noise and spectrum sharing will increasingly be of concern to academic researchers, engineers in government agencies, and engineers in the private sector. The data structures and data sets developed by HCRO-NRDZ will enable large-scale surveys of RF noise to be conducted and to be compared over time and different locations, with potential impact on the design and deployment of future spectrum dependent systems. HCRO-NRDZ will also have an impact on the commercial sector, as HCRO-NRDZ analyses and experiments on bi-lateral spectrum sharing will provide additional data and tools to organizations developing and deploying new systems – and upgrading existing systems – that will be required to share spectrum. The HCRO-NRDZ results will improve the ability of radio astronomy to operate in environments with large amounts of radio frequency interference, particularly as RFI from satellite constellations increases and as radio astronomy instrumentation bandwidths increase beyond the traditional protected bands.

The education domain -ÌýOver the foreseeable future, the demand for RF engineers and scientists is expected to increase. Similarly, issues with RF noise, wireless coexistence, and spectrum sharing will become more prevalent and more complex. HCRO-NRDZ will organize the best practices and lessons learned over the course of the project into a curriculum for educating the next generation of scientists and engineers in the basics of measurement surveys and analyses of both RF noise and spectrum sharing. The HCRO-NRDZ team will conduct workshops on these topics to bring the NRDZ and Radio Astronomy communities together to share knowledge. HCRO-NRDZ activity participation and results will aid to develop national workforce expertise.

The regulatory domain -ÌýSpectrum regulatory agencies in the U.S., the FCC and the NTIA, are grappling with spectrum sharing. The current large-scale examples of spectrum sharing are neither very dynamic, nor bi-lateral. HCRO-NRDZ will further the understanding of the trades involved in spectrum sharing. The studies, analyses, simulations, and experiments conducted by HCRO-NRDZ will inform the spectrum community and the regulatory agencies in the U.S. and abroad about the effectiveness of mechanisms for dynamic spectrum sharing and bi-lateral spectrum sharing. While focusing on mechanisms to protect RA facilities, the results from HCRO-NRDZ will inform more general interactions between spectrum-dependent systems. In addition to publishing results, HCRO-NRDZ will proactively reach out to both the FCC and NTIA to transmit the results of the project.