IEEE DySPAN 2017 Tutorial: Spectrum Access Systems

Monday, March 6th, 2017


The first implementation of large-scale multi-tiered dynamic spectrum sharing is getting under way in the U.S. The FCC has authorized access to the 3550-3700 MHz band under the Citizens Broadband Radio Service (CBRS), where incumbents will share spectrum with underlay services whose spectrum authorizations will be managed by a Spectrum Access System (SAS). This is the first example of SAS-managed spectrum sharing, and expanding the SAS concept to other bands has already been proposed. The purpose of this session is to cover:

  • The policy origin of multi-tiered SAS-managed spectrum sharing;
  • An overview of the SAS rules and implementation details in the CBRS band
  • The regulator’s view of SAS certification and evolution
  • SAS-managed sharing opportunities outside the U.S.
  • Challenges of shared spectrum access under SAS control

We anticipate that the tutorial will be comprised of individual talks, and a panel discussion.


As the welcome message from the DySPAN general co-chairs explains:
[G]overnments around the world are concluding that the approach of clearing spectrum for exclusive use is not viable, and that “sharing” must become the norm.

SAS is the method chosen in the U.S. to implement such sharing in 150 MHz of spectrum primarily occupied by the federal government, and may be a viable option for sharing in other contexts, both within the U.S. and in other countries. For this reason, it is directly relevant to the general objective of the DySPAN conference: A mix of technology and policy issues for exploring advanced spectrum technologies.

Summary and Content

The tutorial will cover the genesis of SAS-based sharing in the U.S., the current rules under which SAS’s operate, the evolution of SAS-based sharing in the near- to mid-future, and the opportunities for SAS implementation elsewhere. Specifically, the following general areas will be covered:

  • Design and operation of spectrum access systems;
  • CBRS as a case study in spectrum access systems;
  • Support for multi-tiered spectrum sharing;
  • The regulators role in spectrum access systems;
  • Incumbent protections;
  • SAS-enabled value-added services
  • Divergent view on the utility of SAS-based sharing.

We anticipate that the material will be covered in a series of invited talks and a panel session.

Intended Audience

  • Academics that could add value to future SAS evolutions (e.g., propagation models, co-existence mechanisms, etc.)
  • Domestic spectrum sharing community that need to learn how SAS works
  • International community looking for additional details on U.S. implementation of SAS
  • Government community, to help understand the implementation details of the CBRS SAS


SAS-controlled spectrum sharing has never been implemented. Less capable methods, such as TV White Space database, have been deployed, but are much more rudimentary than SAS and has not achieved broad uptake.

Previous Tutorials

The Wireless Innovation Forum conducted a public Webinar on the topic of “Understanding the New U.S. 3.5 GHz Band.” There were over 100 participants in the Webinar.


  • Andrew Clegg (Google)

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