By Viet Nguyen, President, 5G Americas – December 2025
Every CTO in our industry is living with the same paradox: the two faces of 5G. In many dense urban markets, operators are delivering 5G experiences that are clearly differentiated from 4G, supporting heavy video usage, fixed wireless access, and early enterprise automation. Yet in other neighborhoods and travel corridors, the user experience still does not consistently reflect the full potential of the standard.
That unevenness is not a mystery. It is the direct result of a network built on a patchwork of radio frequencies, ranging from high-band spectrum that offers immense peak speeds but faces challenges with range and indoor reach, to low-band spectrum that provides broad coverage but only modest capacity. The practical middle of that tradeoff, contiguous mid-band, is where consistent “real 5G” performance is won or lost.
By late 2025, the industry’s center of gravity has shifted accordingly. The 5G-to-6G transition is no longer just a story about radios evolving on a standards timeline. It is increasingly a story about who can secure, clear, and scale large, harmonized mid-band channels, and how fast regulators can deliver them. Auction authority has been restored, FCC proceedings are active again, and multiple mid-band or mid-band-adjacent auctions are now moving through formal comment cycles.
Mid-band spectrum, typically 1 to 7 GHz, is the foundational layer for delivering the true promise of 5G. It is the sweet spot because it balances low-band coverage with high-band capacity, and it fits efficiently into existing macro-cellular grids without requiring the extreme densification that millimeter-wave demands.
Operators have voted with their capital, reflecting the scarcity and strategic value of mid-band under current rules. In the United States alone, investment in mid-band has been staggering:
- Auction 107 (3.70 to 3.98 GHz) closed with roughly USD $81 billion in gross bids, cementing C-Band as the anchor of U.S. 5G capacity strategy.
- Auction 110 (3.45 to 3.55 GHz) added another about USD $22.5 billion in commitments to deepen mid-band capacity nationwide.
The 2025 view is even clearer than it was in 2024. Mid-band is not a future bet. It is the scaling layer operators are building on right now. It is the principal scaling requirement for retaining high-value subscribers, sustaining fixed wireless momentum, and enabling enterprise-grade capabilities such as slicing, private networking, and uplink-intensive applications.
Which is why a predictable national spectrum pipeline is no longer just a policy aspiration. It is a business necessity. Without mid-band depth, the performance gap between “5G in the lab” and “5G in the field” persists.
A “spectrum pipeline” is a long-term plan for identifying and releasing new bands for commercial use. After the FCC’s auction authority lapsed on March 9, 2023, that pipeline stalled at the exact moment operators needed more mid-band to move from coverage to scale. Authority was restored by the One Big Beautiful Bill Act, signed July 4, 2025, and the same law directs a pipeline of at least 800 MHz for commercial use, including at least 100 MHz of Upper C-Band.
What is new in late 2025 is that the FCC has begun formal comment processes tied to upcoming auctions, especially in Upper C-Band and AWS-3. Of course, 5G Americas does not prejudge which bands will ultimately comprise the pipeline. Our priority is a predictable, adequately sized supply of harmonized spectrum across the mid-band range.
Upper C-Band (3.98 to 4.2 GHz)
In late October 2025, FCC leadership circulated a draft Notice of Proposed Rulemaking seeking public comment on auctioning up to 180 MHz of Upper C-Band spectrum, including how much beyond the 100 MHz statutory minimum to clear and how to manage coexistence with radio altimeters in the adjacent 4.2 to 4.4 GHz aviation band. 5G Americas produced a wonderful paper on this issue in 2021.
On November 20, 2025, the Commission voted unanimously to adopt that NPRM, which proposes service rules and bidding procedures for an Upper C-Band auction. Comments are due 30 days after Federal Register publication, with replies 60 days after publication.
This step matters because it moves Upper C-Band from a pipeline concept to active execution. It also surfaces the real obstacles that will define the timetable:
- Fixed Satellite Service incumbents still rely on Upper C-Band for nationwide distribution of television and radio programming, so any reconfiguration will require a negotiated transition and clear reimbursement mechanics.
- Aviation coexistence remains a key dependency. The NPRM explicitly seeks input on technical protections and coordination to avoid altimeter interference, with FAA rulemaking on altimeter resilience running in parallel.
So yes, Congress re-opened the pipeline and the FCC has now kicked off the formal process. But the pace of clearing, inter-agency alignment among FCC, NTIA, and FAA, and incumbent transition logistics will determine how quickly this spectrum becomes deployable.
AWS-3 and other near-term bands
Separately, the FCC’s Office of Economics and Analytics has been advancing the AWS-3 re-auction on a mandated schedule. A Public Notice and related FCC actions in 2025 make clear that an AWS-3 auction (Auction 113) must occur by June 23, 2026, and the FCC is already collecting comment on competitive bidding procedures.
AWS-3 is not symbolic, because it is a legally required re-auction and a meaningful mid-band supplement for many deployment plans. It is a required re-auction of inventory in 1695 to 1710 MHz, 1755 to 1780 MHz, and 2155 to 2180 MHz, with proceeds tied to fully funding the Secure and Trusted Communications Networks rip-and-replace program.
Together, the Upper C-Band NPRM and AWS-3 preparations signal a practical late-2025 reality: the U.S. is back in the auction business, and multiple mid-band or mid-band-adjacent proceedings will move in parallel through 2026.
Looking forward, while today’s 5G networks typically operate on 60 to 100 MHz channels, the transformative use cases envisioned for 5G-Advanced and 6G, including immersive extended reality, digital twins, advanced industrial automation, and integrated sensing, will require a step-change in capacity. That step-change depends on much larger, contiguous blocks of spectrum.
The industry is already coalescing around requirements that shape the next decade of spectrum policy:
- Exact carrier sizes will be defined through standards work, but the trajectory points toward much wider contiguous channels than today, with typical 6G channel bandwidths expected to be on the order of 200 to 400 MHz, based on some discussions.
- Lower bands do not offer enough contiguous spectrum to support those carrier sizes at scale.
- As a result, global attention is shifting to the upper mid-band or FR3 region, roughly 7 to 15 GHz, as the next frontier for balancing bandwidth with coverage practicality.
The fundamental physics and capacity needs of 6G are forcing regulators and industry to look higher up the chart, not as a replacement for mid-band, but as its logical extension.
Historically, making spectrum available for commercial use has meant relocating incumbent users, particularly federal agencies. Clearing remains important, especially in mid-band. But it will not be sufficient for 6G, because many 6G-relevant ranges are tied up with mission-critical government and defense systems that face considerable challenges in order to be moved.
So the future has to be more dynamic. Spectrum sharing can be an important tool in the broader spectrum toolbox, especially where full clearing is impractical. 5G Americas supports exploring sharing frameworks that are technically realistic, protect incumbent missions, and still provide commercial operators with access that is predictable enough to justify large-scale investment. In other words, sharing should expand the pipeline, not become a substitute for the licensed, contiguous spectrum that macro networks still need for nationwide 5G and future 6G performance.
The Commerce Spectrum Management Advisory Committee (CSMAC) “toolbox” concept points in the right direction. It recognizes that coexistence may require combinations of time-based, location-based, and frequency-based coordination, along with power limits and automated enforcement. Where sharing is pursued, it must be built on clear rules, transparent protection criteria, and systems that can operate reliably at national scale.
We already have proof points, but they also illustrate the limits:
- CBRS demonstrates that tiered sharing can work when coordination is automated and incumbent protections are well defined. At the same time, CBRS has also shown that complex sharing rules can create uneven access and uncertain quality of service, which matters when a band is expected to carry wide-area mobile traffic.
- In bands like 3.1 to 3.45 GHz that are heavily used by DoD radar systems, studies have found that sharing is not currently feasible without major advances in technology, processes, and resourcing. That is exactly why 5G Americas emphasizes disciplined pilot work and realistic assumptions about what sharing can deliver in the near term.
- NTIA’s Incumbent Informing Capability work is a valuable step toward more reliable time-based coordination. 5G Americas supports these efforts, with the caveat that informing systems must be accurate, secure, and operationally compatible with carrier grade networks.
But sharing is a tool, not a magic wand. Any dynamic coexistence framework has to confront deep challenges that 5G Americas has been explicit about:
- Trust and verification. Sharing cannot scale if incumbents lack confidence in protections or if commercial operators do not get reliable, timely visibility into when and where spectrum is available. That implies auditable coordination systems and clear accountability.
- Operational complexity. Adding real-time policy engines, sensing, and multi-stakeholder enforcement increases network design and operating burden. Those costs must be acknowledged and minimized through standardization.
- Performance uncertainty. Conditional access changes how networks are engineered. If availability is unpredictable, operators must design for worst-case conditions, which can reduce usable capacity and weaken consumer and enterprise experience.
- Governance and accountability. Sharing regimes require durable rules for interference resolution, enforcement triggers, and dispute pathways. Without that clarity, investment risk rises and access becomes uneven.
Put simply, sharing will be essential in some 6G relevant bands, but it must be implemented in a way that is automated, enforceable, and predictable. Otherwise, it will not deliver the scale or reliability that next-generation mobile networks require.
The market’s verdict on early 5G is clear. A network built on fragmented low-band and high-band layers cannot consistently deliver the experience customers and enterprises now expect. That has created an undeniable mandate: secure large, contiguous blocks of mid-band spectrum to deliver scalable performance and extend that strategy upward into the upper mid-band ranges needed for 6G.
Late-2025 policy actions show that the U.S. pipeline is moving again. The FCC’s Upper C-Band NPRM now puts 100 to 180 MHz of prime spectrum on the table with an active public record underway. At the same time, AWS-3 auction preparations locked to a June 2026 deadline reaffirm that spectrum policy is shifting back into execution mode.
These steps are not merely corrective measures for 5G. They are foundational investments in the technical and regulatory infrastructure that will enable the next decade of wireless innovation, moving our industry from a patchwork present to a truly seamless future.
As we design 6G networks to become more intelligent and more aware of the physical world through integrated sensing, how must we evolve our regulatory models, from allocating static frequencies to dynamically orchestrating spectrum as a shared resource that is vital to both economic growth and national security?
-Viet
