In a series of posts over the past two months I’ve discussed a range of initiatives aimed at using unlicensed spectrum to support the growing demand for wireless connectivity. To put these efforts in a forward-looking context, it’s helpful to get a sense of what changes are in the works in terms of expanding the amount of spectrum available for unlicensed use.
In this post I’m going to focus on the most recent development on this front: the FCC’s April 17 decision to make 150 MHz of spectrum (3550-3700 MHz) available for new licensed and unlicensed commercial use, while retaining protections for existing military and other incumbent users of this spectrum.
First, we are leveraging advances in computing technology to rely on an innovative Spectrum Access System to automatically coordinate access to the band. It’s the traditional frequency coordination role, but modernized using advanced technologies to maximize efficiency.
Second, we are using auctions to grant exclusionary interference protections only when the spectrum is actually scarce. Under our rules, anyone with a certified device can use the spectrum, sharing it with others. In areas where the spectrum is scarce, users can participate in an auction to seek a license to gain priority access to the band.
Third, in cooperation with our federal partners, we are creating a new way to share spectrum with federal users. By leveraging the Spectrum Access System and technologies to monitor and sense when a federal user is present, we can move toward true dynamic sharing of the band between federal and non-federal users.
As a reflection of this cooperation, the Commission, working with NTIA and Department of Defense spectrum users, reduced the latter’s coastal protection zones by roughly 77%.
In her statement, Commissioner Mignon Clyburn pointed to a “paradigm shift [in] the [FCC’s] move away from highly fragmented long term exclusive use licenses to shorter term Priority Access Licenses [PAL] with a rule to use it or share it with General Authorized Access users.”
These new regulatory approaches will create enough certainty to fuel investment in equipment for the 3.5 GHz band and the new PAL license will have lower administrative costs and allow for micro-targeted network deployments. Service providers will have flexibility in designing networks to address unique challenges posed by rural and other areas, and by using a Spectrum Access System database to dynamically assign frequencies in the band for both PAL licenses and GAA users, there will be more efficient use of spectrum in heavily populated areas.
Though the ruling was approved in part and concurred in part by the agency’s two Republican Commissioners, their statements described it not as a “paradigm shift” but rather as an “experiment” that may or may not succeed, and could have been improved in several respects.
For example, Commissioner Michael O’Rielly appeared to disagree with Clyburn about whether the new rules provided enough clarity and incentives for potential PAL licenses to invest:
I am concerned that some rules may hinder development of the Priority Access Licenses, known as PALs. I question whether auctioning PALs for three year terms with no renewal expectancy will create a meaningful incentive to entice auction participants. Similarly, while I thank the Chairman for agreeing to changes that facilitate PALs in areas where there is more than one auction bidder, I had hoped our rules would include a mechanism whereby any entity could receive a PAL even if mutually exclusive applications, which are necessary to trigger an auction, are not filed in a particular census tract. The Commission ought to encourage a diverse array of business models. Many entrepreneurs, even those living in rural communities, have told me of their strong preference for PALs, which they explain would ensure better reliability and quality of service. Our rules must not foreclose these prospective licensees from obtaining PALs just because they are the only one in a given census tract wanting priority access. We need to fix this in the near term.
And, according to Commissioner Ajit Pai:
This Order leaves many important details and complex questions to be resolved, including whether technologies will develop that can manage the complicated and dynamic interference scenarios that will result from our approach. It therefore remains to be seen whether we can turn today’s spectrum theory into a working reality. Moreover, exclusion zones still cover about 40% of the U.S. population, and we leave the door open for the introduction of new federal uses across the country, neither of which is ideal.
Regardless of which description—“paradigm shift” or “experiment”—is most apt, the Commission’s new approach to the 3.5 GHz band strikes me as a worthy effort to move beyond the longstanding spectrum management status-quo, and creatively use technology to explore new models that enable both licensed and unlicensed users to deliver more value from existing spectrum. And, even if some aspects of this new model do prove problematic, it should at least provide valuable lessons to inform future efforts to craft spectrum policy appropriate for the 21st century.
And some aspects of the 3.5 GHz rules remain subject to further refinement, pursuant to a Further Notice of Proposed Rulemaking also issued by the Commission.