The rules that decide the shared band

The notice of August 2024 has produced no order in more than two years

FCC 24-86, adopted on 5 August 2024 and released on the 16th, opened the CBRS rules to change. The replies came in that December, and since then the docket has filled with letters and produced no order (Exhibit 1).

Most of the notice is housekeeping. It proposes to write into Part 96 the federal protections that part 1 describes as resting on notices: the Dynamic Protection Areas, the portal through which the Defense Department switches them on, and permanent protection around eleven ground radar sites. It also covers emission limits, database outages and synchronisation. The argument lives in two paragraphs. Paragraph 53 asks “whether to add one or more classes of higher power CBSDs”. Paragraph 78 asks whether some GAA spectrum should be set aside for private, low-power indoor networks, an idea the Commission turned down in 2015. The notice’s own baseline for the band was more than 370,000 radios and more than 750 certified end-user devices.

The carriers want more power or the band itself

The carriers’ positions are on file, and they differ (Exhibit 2). AT&T’s reply asked the FCC to relocate CBRS users to 3.1 to 3.3 GHz “through an innovative incentive auction”, which would clear “150 MHz for full power, exclusively-licensed deployments”: a request for the band itself. Verizon asked for less: a new Category C radio at 62 dBm per 10 MHz, and phones at 26 dBm. T-Mobile asked for usage data first and warned that changes to power and emissions “may well require relicensing the band”. By February 2026 two of the three, with their trade association, had a wider proposal. CTIA, with T-Mobile and Verizon, told the Chairman’s office that the band lies between the 3.45 GHz band and the C-band. “The Commission has a real opportunity to build a 700+ megahertz contiguous superhighway in the best part of mid-band”, they said.

Verizon’s proposed class is one building class of loss

Today’s ceilings are 30 dBm per 10 MHz for a Category A radio, which is a watt, and 47 dBm for a Category B radio, which is about 50 W. Verizon’s 62 dBm is 15 dB above Category B, and since every 10 dB is a factor of ten in power, that comes to about 32 times. The 72 dBm Category D that DISH proposed in 2021 would be 25 dB above, about 316 times. Brownsville’s waiver request, at 60 dBm, is 13 dB above, about 20 times (Exhibit 3).

The figure of 62 dBm has a physical meaning, which part 3 supplies. Fifteen decibels is the gap between a traditional building and a thermally efficient one at 3.625 GHz, so the proposed class would hand a radio outside the building back roughly one building class of loss. The carriers’ case rests on that, and it is coherent. The users’ case is that the same 15 dB lands on everyone sharing the channel. Valo Analytica studied the question for the advocacy group Spectrum for the Future, with the database operator Key Bridge as technical partner, and found that converting fewer than 2% of CBRS base stations to high power would cause a massive loss of throughput, as Fierce Network reported. Syracuse University put it to the FCC as a “tragedy of the commons”. The Chairman’s office has a question of its own: his adviser, Arpan Sura, said in February 2026 that he wanted to examine whether the more than 400,000 radios in the band are a good indicator of use, as reported.

Verizon’s proposed class is one building class of loss: 15 dB above today’s ceiling, the same 15 dB that separates the two kinds of building. Higher power is in substance a proposal to serve buildings from outside. The indoor and low-power networks that share the channel say they would pay for it in interference, and a shared channel leaves little room for any other outcome.

The statute left CBRS inside the auction pipeline

P.L. 119-21, signed on 4 July 2025, gave the FCC its auction authority back and set a pipeline of 800 MHz to be found between 1.3 and 10.5 GHz. The 6G series sets out its deadlines; what matters here is which bands it protects.

Only two ranges are written out of the pipeline, 3.1 to 3.45 GHz and 7.4 to 8.4 GHz, each “for purposes of auction, reallocation, modification, or withdrawal”. Two consequences follow for the shared bands (Exhibit 4). First, AT&T’s proposed home for CBRS users, 3.1 to 3.3 GHz, is now a band the statute bars from that kind of change. Second, 3.55 to 3.7 GHz is inside the covered band and nothing excludes it; the same applies to 5.925 to 7.125 GHz.

The FCC’s own obligation is to auction 300 MHz, and the statute names no band for it beyond 100 MHz of upper C-band. Its first order, FCC 26-46 of 22 July 2026, takes 160 MHz there, which leaves at least 140 MHz still to find by 30 September 2034. NTIA’s first 200 MHz of federal spectrum is due on 4 July 2027. Neither the statute nor anything on the record says whether the shared 3.55 to 3.65 GHz counts as “allocated for Federal use” for that purpose.

The same order touches CBRS directly. It raised the power limit for phones across 3.7 to 4.14 GHz, the band immediately above CBRS, from 1 W to 2 W. The Commission chose 2 W “out of an abundance of caution”, against the 4 W that AT&T, Verizon, CTIA and Qualcomm had asked for. The CBRS users had asked for the change to wait for coexistence studies, and the order replied that they “have not outlined detailed concerns with, or presented any specific analysis of, the potential impacts on CBRS operations”. For anyone arguing the power case in the main docket, that sentence is the lesson.

The statute closed the route AT&T proposed for moving CBRS users and left the band itself unprotected. The FCC’s first order under it raised power at the band’s upper edge over its users’ objections. Nothing on the record has started a relocation. A user faces rules that have stayed undecided for more than two years and could be decided at any meeting.

The other shared band moved the other way

The contrast with 6 GHz is sharp. That band, 1,200 MHz from 5.925 to 7.125 GHz, was opened to unlicensed use in April 2020, and every FCC action since has widened that use (Exhibit 5). Very low power devices were allowed anywhere in two of its sub-bands in November 2023 and in the other two in December 2024. Seven automated frequency coordination systems, the databases that set the power of standard-power access points, were approved in February 2024, and the FCC says it has received no interference complaints about them. On 29 January 2026, in FCC 26-1, the Commission created geofenced variable power devices in two sub-bands at up to 24 dBm EIRP, indoors and outdoors, with Commissioners Carr, Gomez and Trusty all approving. The rules took effect on 27 April 2026 (91 FR 9140). The order’s further notice proposes letting the databases count up to 6 dB of building entry loss.

For an enterprise the comparison is direct. One shared band has an open rulemaking, proposals on file to raise its power or move its users, and a statute that leaves it unprotected. The other has the same statutory exposure and six years of decisions, all in one direction. In 2026 the 6 GHz rules are the more settled of the two by some distance.

Renewal and the other obligations inside buildings

The notice proposes no change to PAL renewal, so the test that part 1 dates to 12 March 2031 stands as it is: substantial service, shown from radios registered with a database. Two other rules bear on a building owner, and neither is about CBRS.

• Signal boosters. Under § 90.219 a building owner may run a booster on public-safety or private land mobile frequencies only with “the express consent of the licensee(s)”. A wideband (Class B) installation has to be registered in the FCC’s signal booster database. Only a distributed antenna system inside a building may carry commercial and public-safety bands together.
• FirstNet. FirstNet now brings its own band indoors at public-safety sites. Its FY2025 report records 5,546 units supplied to agencies to extend Band 14 coverage inside, “providing up to approximately 85 million square feet of indoor coverage”. The task order behind them requires AT&T to extend that coverage to public-safety facilities.

Terms used

• Notice of proposed rulemaking. The FCC’s formal proposal to change its rules. It binds nobody until a report and order adopts it.
• Ex parte. A filing that records a meeting or letter with FCC staff about an open proceeding, in the filer’s own words.
• Category C and D. Proposed CBRS radio classes above today’s Category B ceiling of 47 dBm per 10 MHz: 62 dBm and 72 dBm.
• Covered band. The statute’s name for 1.3 to 10.5 GHz less its two excluded ranges, from which the pipeline’s spectrum must come.
• AFC, automated frequency coordination. A database that sets the power a standard-power 6 GHz access point may use at its location, to protect fixed microwave links.