AT&T’s CBRS Proposal May Not Advance in Full, but DoD Support Reflects Changing Attitudes Toward Shared Spectrum

In early May 2025, reports surfaced that the U.S. Department of Defense (DoD) had expressed support for a controversial proposal led by AT&T to relocate Citizens Broadband Radio Service (CBRS) users out of the 3.55–3.7 Gigahertz (GHz) band and move them into the lower 3.1–3.3 GHz range. The goal is to consolidate a contiguous block of exclusive, high-power spectrum by aligning the 3.45–3.55 GHz band with the adjacent C-band (3.7–3.98 GHz), effectively sidelining the shared-use model that defines CBRS.

If implemented, this move could fundamentally alter the role of the CBRS band in the U.S. spectrum landscape. While the proposal does not immediately eliminate CBRS, it would significantly diminish its long-term utility and economic viability by shifting users into a band currently dominated by federal incumbents. Critics argue that the proposal favors large Mobile Network Operators (MNOs) at the expense of innovation and diversity, disrupting the ecosystem of enterprises, utilities, rural Internet Service Providers (ISPs), and neutral hosts that have invested heavily in CBRS-based deployments.

AT&T's concept calls for repurposing a contiguous 100 Megahertz (MHz) block—either by reallocating a portion of the current CBRS spectrum or integrating adjacent federal holdings—for exclusive, high-power 5G use. This block would be made available via traditional spectrum auctions to nationwide MNOs, potentially replacing or reducing the current three-tiered sharing model that underpins CBRS. Under the current model, incumbent federal users, Priority Access License (PAL) holders, and General Authorized Access (GAA) users coexist through dynamic coordination enabled by Spectrum Access Systems (SASs).

If approved in full by the Federal Communication Commission (FCC), AT&T’s proposal to reallocate CBRS spectrum could severely disrupt the U.S. CBRS ecosystem. With over 400,000 active CBRS devices—most operating under GAA—the change would jeopardize thousands of rural, enterprise, and industrial networks, forcing costly migrations or shutdowns. It would also undermine key stakeholders like rural ISPs, cable operators (e.g., Comcast and Charter), and neutral host providers (e.g., Federated Wireless, Boingo Wireless, Boldyn Networks), all of which rely on CBRS for affordable, shared-spectrum solutions. The loss of this model could reverse progress on spectrum innovation, reduce indoor and localized connectivity options, and widen the digital divide. However, it should be mentioned that this is not the first time that carriers tried to undermine/alter the CBRS framework to increase influence over spectrum regulation.

Given the grave consequences and the fact that carriers have been trying to lobby for CBRS spectrum before, it is unlikely that the FCC will adopt these measures straight away. Undoubtedly, though, this proposal is a sign that spectrum sharing arrangements like CBRS are under attack and that the policy momentum may be shifting back toward exclusive licensing models that prioritize nationwide carriers over decentralized innovation and localized access. There are several possible avenues through which the CBRS framework can be undermined over time:

1. Power Level Reforms for PAL Licenses: To address some of the demands from CSPs, proposed reforms would allow higher power levels for PALs. However, these increased power levels could lead to greater interference with GAA users, potentially reducing spectrum availability and reliability for non-carrier deployments. Different parties (both from the enterprise and telco sides) have been pushing for the power restrictions to be lifted, so this will be a likely short-term move. As a result, there may be a heightened need for SAS platforms and advanced interference management solutions.
2. Reduction of GAA Access in High-Demand Areas: In cities and other high-demand areas, spectrum congestion will increasingly favor PAL holders, leaving GAA users with fewer, less reliable channel options. In addition, increased pressure from carriers and their lobbying efforts within the administration might push the FCC to allow PAL licensees to expand usage or reconfigure spectrum access rules in ways that crowd out GAA access, particularly in dense, commercially valuable regions. Such a move would particularly affect rural ISPs, school districts, hospitals, or smart cities, as they often rely on low-cost GAA for fixed wireless or even private cellular networks. Without formal reallocation, GAA spectrum could become functionally unusable in key markets, forcing users to abandon CBRS or invest in costly alternatives.
3. Policy Drift Through Regulatory Delay or Inaction: Even without a change of formal rules, there are ways in which the FCC can weaken the CBRS framework through regulatory inaction, which may create uncertainty and can discourage long-term investment. This can range from delaying future PAL auctions and a lack of updates on the protection of GAA users to not providing any forward-looking roadmaps around future regulatory efforts. While this uncertainty will hit all companies in the CBRS ecosystem, larger players (such as national carriers) will be better positioned to weather this uncertainty. Smaller, more specialized players, like neutral host vendors or rural broadband providers depend on predictability and might, in the long term, choose to exit the market. This ongoing uncertainty presents the worst possible outcome. Therefore, it should be the goal of every player within the industry (regulator, telco service provider, and infrastructure vendor) to avoid unnecessarily long ambiguity and provide policy clarity quickly.

Even though it is unlikely for the FCC to approve the proposal made by AT&T in its entirety, the endorsement of these plans by the DoD should act as a wake-up call for the companies in the ecosystem to start preparing for gradual changes to the CBRS framework. This contingency planning should entail different elements. While the FCC should do everything possible to minimize disruptions to the current CBRS framework to an absolute minimum, infrastructure vendors and service providers should advance their contingency planning to be prepared for reforms to the CBRS framework.

First, infrastructure vendors should accelerate building spectrum flexibility into solutions and roadmaps. First and foremost, this implies designing products with multiband support in mind. It is expected that with the imminent changes to the CBRS band, adjacent bands will grow in importance. Consequently, infrastructure and component vendors should look at building in support for C-band spectrum or the 4.9 GHz band (under state or public safety licensing). In addition, infrastructure and component vendors also need to start working on migration paths for current CBRS users, including fallback options to licensed or unlicensed spectrum. This could entail integrated software-defined spectrum switching (to give enterprises flexibility in the event of interference, licensing changes, or future upgrades), the creation of migration toolkits (professional service offerings to help existing CBRS customers plan for contingencies), and ecosystem partnerships for easier access to licensed operator spectrum.

Second, infrastructure/component vendors, as well as CSPs and WISPs, should strengthen interference and operational resilience. To do so, they should look at deepening integration with SAS providers for more granular, real-time frequency coordination. Furthermore, they should explore dynamic access options to minimize channel contention interference. By integrating Artificial Intelligence (AI)/Machine Learning (ML) capabilities, infrastructure vendors can furthermore increase the adjustability of their equipment to adjust power levels, antenna tilt, channel assignment, and spectrum use.

Third, this can serve as an opportunity for infrastructure vendors, CSPs, and WISPs to embrace the dynamic nature of the CBRS framework and become proactively involved in shaping the framework and developing the ecosystem accordingly. This can include participation in policy advocacy groups—despite shifting their focus to educating the market about the benefits of CBRS and private cellular—the OnGo Alliance will remain an important voice in the policy field. Furthermore, vendors and service providers should be prepared to create policy briefs and market education documents to emphasize the value of shared spectrum and the risks of regulatory drift. To maximize the impact, these briefs should rely on consolidated and aligned messages from a range of ecosystem partners to present a unified voice on the need to preserve CBRS's shared access model.