FCC Proposes Spectrum Sharing Model for the CBRS

By Lawson Faulkner

The FCC is seeking public comment on a collection of proposed rule changes for the Citizens Broadband Radio Service (CBRS), a 150 MHz spectrum band available for both commercial and federal government use. Most notably, one proposal would sunset the “transition of grandfathered wireless broadband services in the 3.65-3.7 GHz band”, freeing up spectrum access for countless American businesses.

In 2015, the FCC adopted a three-tiered access system for shared use of the 3550-3700 MHz spectrum band. Prior to the creation of the CBRS, these frequencies were largely reserved for U.S. military communications, such as aircraft transmissions and naval radar systems. However, following the mass deployment of private 4G and 5G cellular networks, the FCC moved to reappropriate this spectrum band for commercial use.

Within the CBRS, three access tiers are regulated by an audio frequency coordinator, also known as a Spectrum Access System (SAS). This is meant to prevent spectrum interference for prioritized CBRS users such as the U.S. military. However, due to the existence of “grandfathered wireless broadband licenses”, some commercial enterprises enjoy premium CBRS access as well. This aspect of the service has been a point of tension among other commercial participants within the CBRS. While low-tier commercial participants are relegated to low spectrum frequencies, grandfathered licensees enjoy a duopoly with the U.S. military for the 3650-3700 MHz spectrum band.

For instance, within the third tier, general authorized access is granted to unlicensed commercial enterprises such as private cellular networks. Within the second tier, priority access licenses (PALs) are granted to individual U.S. counties based upon a competitive bidding process. And lastly, within the first tier, incumbent access is granted to fixed satellite services, U.S. military communications and grandfathered broadband licenses.

On June 13th, FCC Chair Julia Rosenworcel moved to end this grandfather system, championing her agency’s “continued commitment to developing, and improving, spectrum sharing models that provide opportunity for expanded use of the airwaves.” Through a newly proposed rule, the FCC would sunset the transition of five-year commercial licenses within the 3650-3700 MHz spectrum band, while simultaneously strengthening incumbent protection for federal CBRS users.

This move would level the playing field for commercial CBRS participants, ensuring that high-speed spectrum bandwidths are no longer dominated through long-term licensing.

In recent years, the CBRS status quo has grown unsustainable due to expanded 5G network deployment. With commercial providers demanding higher spectrum thresholds, the existence of incumbent licensing within the CBRS cannot continue. Through a redistribution of spectrum access, low-tier commercial participants will no longer be handcuffed to spectrum frequencies that do not meet the technological moment. According to FCC Chair Rosenworcel, this level of “cooperation is critical for a successful spectrum future.” By instituting an egalitarian sharing model, the next generation of commercial spectrum services will have access to the bandwidth they need to thrive. When faced with future questions concerning the redistribution of finite spectrum bandwidth, lawmakers should favor a model that incentivizes open-access innovation, rather than a stagnated licensing status quo.