Tony: Hello, I’m Tony Mangino from TC2, and this is Staying Connected —the podcast where we talk about what really matters to enterprise customers navigating today’s technology and sourcing decisions.

In an ongoing series of podcast episodes, Steve Rosen and I have been following the conflict between 5G deployment and aircraft radio altimeters. We now have a major development: the FCC released its final Upper C-Band Report and Order, FCC 26-46, on July 24, 2026. Steve is a partner at LB3 whose practice includes FCC regulation of wireless services. Steve, welcome back to our show.

Steve: Thanks, Tony. This order gives us a different ending from the lower C-band story. The engineering is harder because wireless operations will be closer to the radio altimeter band. But this time the FCC, FAA, wireless industry, and aviation industry worked toward a coordinated solution before deployment.

Tony: Before we get into the technical protections, remind us why the FCC had to move now. This wasn’t simply the Commission deciding that it wanted another spectrum auction, correct?

Steve: Correct. Congress stepped in through the One Big Beautiful Bill Act. That law restored the FCC’s general auction authority and directed the Commission to complete an auction for at least 100 megahertz of upper C-band spectrum by July 4, 2027. The FCC chose to exceed that floor. The order makes 160 megahertz—3.98 to 4.14 gigahertz—available for terrestrial wireless licenses. It also establishes a separate 20-megahertz guard band from 4.14 to 4.16 gigahertz. So the broader reconfigured segment runs to 4.16, but the licensed spectrum itself stops at 4.14.

Tony: That distinction matters, especially when we compare the spacing with the lower C-band. Can you put the two band plans side by side in plain English?

Steve: Sure. Radio altimeters operate from 4.2 to 4.4 gigahertz. Under the 2020 Lower C-Band Order, wireless licenses ended at 3.98 gigahertz, leaving 220 megahertz between wireless operations and the bottom of the altimeter band. Under this new plan, the reconfigured upper C-band reaches 4.16 gigahertz, leaving only about 40 megahertz before the altimeter band begins at 4.2. That is dramatically less frequency separation, even though the last 20 megahertz of the reconfigured segment is itself a guard band.

Tony: So, if the upper C-band sits much closer to this safety equipment, then what keeps a wireless signal from spilling into the altimeter frequencies?

Steve: The first answer is a tougher out-of-band-emissions limit. OOBE is radio energy that leaks beyond a transmitter’s assigned channel. The lower C-band originally used the standard negative 13 dBm-per-megahertz conducted-power limit. The new order specifically reduces emissions entering the 4.2 to 4.4 gigahertz altimeter band by setting an EIRP limit of negative 28.4 dBm per megahertz or a conducted-power limit of negative 46 dBm per megahertz. And, the Commission harmonized that rule across wireless operations from 3.7 to 4.14 gigahertz, creating one long-term framework. Since 2023, lower C-band licensees have voluntarily observed an even lower negative 48 dBm-per-megahertz conducted limit into the altimeter band, but those temporary commitments were not permanent rules.

Tony: The order also addresses antenna height. Why does that matter to an aircraft?

Steve: A taller antenna can change an aircraft’s RF exposure, particularly near the ground. In 2020, the FCC imposed no C-band-specific height restriction beyond ordinary air-navigation requirements. The new order caps upper C-band transmitting antennas at 450 feet above ground level. That number reflects cross-industry consensus—aviation and wireless engineers identifying a practical boundary together.

Tony: That sounds like one of the biggest changes from 2020—the process, not just the numbers.

Steve: It is. In 2020, the FCC concluded that the Aerospace Vehicles Systems Institute study put in the record by the aviation industry did not show likely harmful interference under reasonable scenarios. It encouraged a multi-stakeholder group, but over the objection of the aviation industry, it imposed no retrofit mandate, C-band-specific antenna-height cap, or aviation funding. In late 2021, the FAA warned that unresolved concerns could severely restrict the National Airspace System, and White House involvement helped broker mitigations. Carriers reduced power near airports, and airlines completed targeted altimeter work by September 2023. The new order reflects those lessons.

Tony: One of those lessons seems to be that transmitter rules alone are not enough. What is the FAA doing on the aircraft side?

Steve: The FAA issued a companion final rule requiring covered radio altimeters to satisfy an Interference Tolerance Mask, usually called the ITM. In everyday language, the ITM defines how resistant an altimeter must be to signals outside its assigned band. The FCC controls the wireless transmitters; the FAA controls aviation safety. By aligning the FCC’s network rules with the FAA’s receiver-performance rule, the agencies are addressing both sides of the interference equation.

Tony: Walk us through the retrofit schedule, because there are two deadlines and a very large number of aircraft.

Steve: The first deadline is December 30, 2030. It covers U.S. registered commercial aircraft and the larger foreign-registered aircraft—8,662 aircraft with 18,423 radio altimeters in the FAA’s forecast. The second deadline is October 31, 2034. It covers the remaining aircraft subject to the rule, including all private airplanes. Across all categories, the FAA forecasts 43,562 aircraft and 62,810 radio altimeters.

Tony: For the airlines, this is the second retrofit campaign in less than a decade. Is this the “one-and-done” solution aviation had been asking for?

Steve: That is the objective. Commercial operators already performed the more targeted lower C-band work in 2023. Aviation stakeholders did not want to modify aircraft repeatedly as more spectrum came online. The new ITM-based standard is meant to provide a durable level of interference tolerance for the full C-band environment. Of course, “one and done” does not mean simple or cheap. The FAA estimated the broader program at $4.49 billion, while aviation stakeholders said the cost could reach or exceed $7 billion. Design, certification, manufacturing, installation, and aircraft downtime all drive that range.

Tony: Which brings us to the question we raised in the last episode: who pays?

Steve: The FCC’s answer is a rebate program. New upper C-band licenses are conditioned on funding rebates for eligible owners and operators that complete the work. Auction winners fund the program, and the Upper C-Band Clearinghouse administers it. The first phase generally covers qualifying U.S. Part 119 operators (airlines, private charters, and large private jets); the second follows ownership on the FAA Aircraft Registry, or all aircraft registered in the United States (displaying “N” or “November” on its tail). Foreign-registered aircraft, spare inventory, and altimeter manufacturers are excluded from the rebate program for now, but foreign aircraft owners have filed suit in the DC circuit seeking to overturn that part of the FCC’s order. The lower C-band provided no comparable support.

Tony: What happens between now and the end of 2030? The lower C-band networks are already operating, and not every aircraft will immediately meet the new ITM.

Steve: The lower C-band licensees agreed to extend their existing voluntary technical commitments from their prior 2028 expiration until the FCC’s Primary Transition Deadline on December 30, 2030. Those commitments bridge the gap while the first aircraft group is retrofitted and the upper C-band is cleared. After that deadline, the voluntary commitments are expected to expire in full, and the new harmonized FCC technical rules take over. In the primary markets, upper C-band wireless operations may begin on December 31, 2030.

Tony: Let me see if I have the comparison right. In 2020, there was a 220-megahertz separation, no special antenna-height limit, a negative 13 dBm-per-megahertz conducted emissions rule, no mandatory fleetwide retrofit plan, and no aviation funding. In 2026, the separation is about 40 megahertz, but the FCC adds stricter emissions controls, a 450-foot antenna cap, FAA-mandated receiver upgrades, firm deadlines, and auction-winner-funded rebates. Fair summary?

Steve: That’s exactly right. The counterintuitive point is that the new allocation is closer to the altimeter band, but the regulatory package is much more protective and much more coordinated. The Lower C-Band Order largely relied on frequency separation and future collaboration if a problem developed. The Upper C-Band Order builds collaboration, transmitter limits, receiver standards, implementation dates, and financial support into the plan before wireless service begins.

Tony: So, what dates should listeners put on the calendar from here?

Steve: The FCC must complete the auction by July 4, 2027. December 30, 2030 is both the first retrofit deadline and the Primary Transition Deadline, with service in primary markets able to begin the following day. The remaining covered fleet must comply by October 31, 2034. Certifying and installing safety-critical avionics across more than 43,000 aircraft takes years, so continued cross-industry work will be essential.

Tony: That’s a useful place to leave it: closer spectrum, stronger rules, and a much more collaborative flight plan. Steve, thanks for translating a complicated order for us today. And to our listeners, if you’d like to learn more about how upper C-band deployment may affect your business, or if you’d like to discuss other ICT needs with Steve or me, or any of our LB3 and TC2 colleagues, please give us a call or send us an email. You can also stay current by subscribing to Staying Connected, checking out our websites, and following us on LinkedIn.