Dean Bubley: CBRS Shared Spectrum Critical for U.S. Wireless Innovation

Editor's Note: This is the first of a two-part series by Expert Opinion author Dean Bubley about shared spectrum. The second piece is scheduled for Friday, Jan. 16, 2026.

The recent Americas Spectrum conference in Washington had a central focus on changes to mobile and unlicensed spectrum bands, as well as satellite frequencies and operations.

The One Big Beautiful Bill Act (OBBBA) mandate to the Federal Communications Commission and the National Telecommunication and Information Admnistration to find 800 megahertz of spectrum for auction was referenced in almost every session, as well as in conversations among attendees outside the hall.

While the mobile industry is very enthusiastic, various other existing users and licensees of bands below 10 GigaHertz (GHz) are concerned that they may be forced to move or consolidate operations, to provide space. 

One of the topics under discussion was the future of the shared Citizens Broadband Radio Spectrum (CBRS) band, between 3.55-3.7 GHz. This is used by a variety of wireless carriers, rural wireless ISPs (WISPs), cable operators, enterprises and in-building coverage specialists – as well as defense-sector incumbents.

In particular, there appear to be worrying risks for the third tier of users, known as “general authorized access” (GAA) operators, which is a hugely diverse group of organizations ranging from schools to manufacturers, as well as many WISPs and others. This group has dynamic access to the parts of the CBRS band which are “left over” after the incumbents and licensed PAL (Priority Access License) users are protected.

The good news is that the bulk of near-term spectrum for auction should come from the upper C-Band, between 3.98-4.20 GHz. In addition to the conference speeches from policymakers, there is already an official FCC announcement and notice of proposed rulemaking (NPRM) which highlights up to 180 megahertz for auction by the first OBBBA deadline of July 2027.

This fits into the FCC’s target of 300 megahertz of existing commercial bands, which runs alongside NTIA’s requirement to find the remaining 500 megahertz from federal spectrum allocations.

But this still means other spectrum bands must be evaluated to meet these tranches’ quotas, and some fear that CBRS could still be targeted in some way.

Indeed, while recent speculation about revisiting the 6 GHz unlicensed band has been strongly rebuffed by officials including Arielle Roth from NTIA speaking at the conference, the discussions and protections around CBRS were less clear. 

CTIA members, notably AT&T, have previously suggested “moving” the CBRS band, and instead reverting to the traditional cellular model of auctioned, licensed, high-power spectrum for normal mobile and 5G Fixed Wireless Access (FWA) usage.

Indeed, some of the traditional mobile carriers want to reorganize the whole 3.1-4.2 GHz spectrum band, with almost all of it dedicated for high-power, exclusive use by a small number of big telcos, with just the lower part between 3.1-3.45 GHz shared by military and other users.

This “public cellular extremist” position has been strongly rebuffed by almost everyone else, given the criticality of CBRS to companies from manufacturers to oil and gas, airports and utilities, as well as numerous healthcare and educational institutions, and rural WISPs. 

However, it is clear that the political complexity and high costs of such major or “existential” changes to CBRS are becoming more apparent and understood. Such a move would involve cancelling the PAL licenses, auctioned in 2020 with 10-year renewable terms, with a strong likelihood of protracted legal action. It would also involve moving or renewing Navy radars, which could take many years.

There have been vague suggestions of somehow “relocating” CBRS to another band, although it is unclear which frequency range is proposed, or what would happen to any incumbents. There would in any case be a need to recreate the standards, SAS system, devices and chipsets that support today’s extensive Band 48 ecosystem – again, a years-long exercise.

Since the conference, FCC Commissioners Anna Gomez and Olivia Trusty have spoken positively about CBRS, which reflects it retaining significant support in Washington. This followed a pro-CBRS September letter from 10 Republican senators. The “nuclear option” seems to be fading as a possibility. But that does not mean the band could not still be targeted in a more subtle way. In 2024, the FCC ran a consultation as part of another NPRM about CBRS, that highlighted a variety of possible vectors for change. But yet, there have been no proposals advanced, reflecting the US election and new administration (and FCC leadership) in the interim period.

The most realistic risks remaining are that the FCC either slices some spectrum off the top of the CBRS band for auction, or that it significantly increases the permissible power of the base stations and changes the interference limits, or out-of-band emissions. 

Either of those scenarios could make the GAA tier substantially less useful or even completely undermine it. Firstly, the bulk of current CBRS installations use GAA. There are growing demands for more such spectrum, especially in areas where there may be multiple private networks in close proximity to each other, such as airports or cities. Reducing the size of the band for dynamic GAA access would severely constrain the options for such networks.

High-power usage of CBRS for normal mobile networks, with lower out of band emission constraints, could “sterilize” large areas and prevent other smaller providers using either the same channels, or potentially neighbouring channels. That would be extremely harmful for many enterprises wishing to deploy private 5G networks, or rural users dependent on WISPs. 

It would also require a lot of re-working and re-testing of the dynamic Spectrum Access System (SAS) database which grant access to each tranche of spectrum – and potentially roll back many of the gains from the 2024 CBRS 2.0 enhancements, which reduced the size of the “dynamic protection areas” by the coasts and extended CBRS reach to 72 million more people.

While there has been significant innovation by some PAL licensees, notably a few large enterprises such as John Deere, the majority of genuinely new use-cases, and much of the broader CBRS ecosystem of device and solution vendors, has been catalyzed by the potential of GAA. 

From school systems deploying campus networks, to “neutral host” indoor wireless providers and even “personal” or “decentralized” networks created by companies such as Helium, the GAA tier of CBRS has meant a leading position for the US in private and local cellular networks. While not all concepts and suppliers have had outright success, that is the hallmark of true innovation – GAA allows for “permissionless” invention and R&D. 

It is broadly the same principle as the Internet itself, fostering entrepreneurial spirit and a much wider base of creators, experimenters and venture capital. Coupled with developments in AI and IoT, it is leading to both “mainstream” private networks for enablement of critical industries and US manufacturing re-shoring, and to leading-edge developments that go well beyond the scope of a handful of traditional mobile operators.

Indeed, rather than looking to constrain, shrink or move CBRS and re-concentrate 5G with the large public carriers, a better approach is to revisit the CBRS rules and SAS / dynamic-sharing model to better reflect the needs of “innovative” users such as enterprises. 

But because the “long tail” of GAA-centric CBRS innovators is so diverse, it lacks a singular voice on spectrum issues, especially in Washington, DC. Some of its policy and spectrum concerns are surfaced by groups such as the OnGo Alliance, Spectrum for the Future, and the new 5G-OT Alliance and American-Made 5G organizations.

In summary, despite somewhat greater clarity on future OBBBA-inspired spectrum policy, there is still a significant risk to the CBRS ecosystem, especially among the GAA tier. Policymakers should avoid disrupting an important, world-leading industry sector – and the numerous US communities and enterprises that depend on easy, flexible access to spectrum for a huge range of applications and devices.

Dean Bubbly is the Founder of Disruptive Analysis. He is one of the leading analysts covering 5G, 6G, Wi-Fi, telco business models & regulation, the future of voice/video, and the emergence of technologies such as quantum networking and AI. This Expert Opinion is exclusive to Broadband Breakfast.

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