Current and Future Directions in Spectrum Sharing Martin Weiss University of Pittsburgh Pittsburgh PA USA mbw@pitt.edu

Overview Current actions in the US Underlying factors Conclusions & research frontier

Overview Recent developments in spectrum bands (covered in more detail by Doug Sicker) TV White Spaces CBRS in the 3.5 GHz band 5.8 GHz Satellite C-Band downlinks Other sharing Model city (from PCAST) Philadelphia spatial measurement project More generally CSMAC process “Bi-directional” sharing

Underlying questions How do we build “social capital” in the spectrum sharing ecosystem? What is the “low hanging fruit” of the spectrum sharing ecosystem that we can focus on? What are we building the ecosystem for?

What do we mean by the “spectrum sharing ecosystem”? Constituents Regulators Incumbents Entrants Spectrum Managers/Database operators NGOs Governments Military Broadcasters Institutions Resource definition Resource governance Enforcement Technologies Software/Cognitive radios Spectrum Access Systems Environmental Sensing

Institutions Resource definition Resource governance Enforcement Spectrum allocation and assignment methods Framework for negotiating the terms of sharing Resource governance Nested hierarchy? Collective action rights Enforcement

What is “social capital” and how do we build it? The foundation on which we interact with each other Reduces “transaction costs” Building social capital Experience and history Clear rights and rules Predictable outcomes from dispute adjudication A note on rights enforcement Involves potentially all stakeholders Goes beyond usage rights (i.e., interference) and includes collective action rights

Enforcing collective action rights Including governance mechanisms enables CPR governance Accountability Locally devised rules Nested governance Enforcement We can modify this figure as illustrated, which improves the likelihood of effective CPR governance and sustainable management. This may be desirable because decentralized management can be more efficient than centralized management. Engaging stakeholders also can reduce the perceived risk, enhancing the likelihood of spectrum sharing.

What is the “Low Hanging” fruit? What I learned from 15 years of DSA research We (the community) were seduced by the challenging technical problem of distributed “non-cooperative” cognitive radio systems Bypassed the “cooperative” approaches – until TV White Spaces How does this apply? Address the “easy” problems first Address the “most likely to occur” problems first Address problems that have a greater impact on building social capital first

“Low hanging fruit” examples Enforcement infrastructure for “routine” events Fixed sensor network (sensing as a service) for environmental sensing Use “citizen science” framework to build data about spectrum environment

Purpose of the sharing infrastructure Lessons from unlicensed services Platform for innovative new service

Toward a research agenda Numerous meetings have taken place Research future meeting at DySPAN 2015 US National Science Foundation (NSF) Enhance Access to Radio Spectrum (EARS) Report (http://www.nsf.gov/mps/ast/2015_ears_workshop_final_report.pdf) Spectrum Measurement workshop (http://www.cs.albany.edu/~mariya/nsf_smsmw/) Wireless System Research and Development (WSRD) workshops (https://www.nitrd.gov/nitrdgroups/index.php?title=Wireless_Spectrum_Research _and_Development) Perhaps others elsewhere in the world What are the “tall poles in the tent”?

Example: Grand Challenges from the NSF EARS workshop Achieving harmonious coexistence in heterogeneous wireless networks and systems Development of automated enforcement mechanisms and compliance certification methods Evolving spectrum sharing architectures for future wireless applications and usage scenarios Exploration of emerging technologies as a vehicle for bold new approaches, including academic-industrial-regulatory interaction

Discussion?