The US should consider spectrum-sharing in the 4GHz band instead of clearing federal users entirely. Shared, flexible licensing could support 5G/6G innovation, protect government operations, reduce costs, and enable localized, AI-driven wireless networks through intelligent coexistence models.
The US can unlock significant benefits by allowing more commercial use of existing Federal spectrum bands. Done well, there is potential for both direct economic gains and broader stimulus for innovation. It could also benefit federal users themselves, many of which could take advantage of cheaper, more flexible commercial equipment.
In other words, there is real scope for “win-win” outcomes from spectrum commercialization without undermining national security or other essential capabilities such as emergency response and satellite communications.
Evaluate all options for commercialization; not just clearance and auction
The methods of commercialization and spectrum release need close scrutiny. In particular, even with the OBBBA spectrum objectives, policymakers need to systematically and objectively evaluate spectrum-sharing as a potential viable option. The finite nature of spectrum and the growing divsersity of users and applications demanding wireless access requires close evaluation, especially as to whether spectrum sharing can meet multiple commercial needs.
It is simple and easy to say “clear a federal band of incumbent spectrum users, and auction it for commercial use by mobile carriers”, but it often turns out to be much harder to do it in practice.
There are multiple trade-offs involved. The real question should be “can we achieve meaningful new commercial use while preserving incumbent performance and mission resilience, and without paying an excessive price in time, cost, and operational risk?”
So instead of jumping immediately to the “clearance” option – which may turn out to be near-impossible, prohibitively expensive or involve some deeply unpalatable decisions – there should be a systematic evaluation of other efficient and potentially less disruptive alternatives.
Some bands — such as the 4.4-4.9GHz range (“4GHz band” in this article) — might be better suited to some form of spectrum-sharing arrangement, either on a permanent basis or during a sensible transition period, as opposed to the blunt and disruptive tool of clearing incumbents and auctioning exclusive spectrum.
In particular, commercial 5G and future 6G may be better served by coexistence with existing federal government and other users – and indeed, that coexistence mechanism itself may be a valuable domain for innovation, efficiency and U.S. leadership.
Existing 4GHz incumbents will be challenging to move. Coexistence may be easier
In the United States, the 4GHz band is known to be used by about 15 different federal government agencies, with multiple different applications and thousands of registrations. While some of these may be replaceable or moveable, others will prove to be far harder, excessively costly or even impossible to shift.
In brief, the types of systems active in the 4GHz band include:
- 4400 – 4500 MHz: Used nationwide by various Federal government bodies for fixed and mobile services, in both civilian and defense sectors. Applications include military training, fixed line-of-sight and transportable microwave communications systems, drone control and telemetry systems. It is also used by civilian Federal agencies for managing nuclear emergencies and law enforcement operations.
- 4500 – 4800 MHz: Used for DoW training exercises at military facilities, air-to-ground operations, flight telemetry and aeronautical video / telemetry downlinks. Other applications include video systems for law enforcement, drug interdiction missions and nuclear emergency response. Portions are also used for non-federal international fixed-satellite service.
- 4800 – 4940 MHz: Used by military agencies at test ranges and naval ports around the country, for a variety of applications. It is also used for law enforcement and drug interdiction missions, plus non-federal radio-astronomy at selected locations.
The 4GHz band also has a broader geopolitical context. Segments of the range are used for NATO communications and control systems by the US and its allies. In Europe in particular, there is significant pushback against designating 4.4–4.8 GHz for high-power IMT (5G/6G) as a primary application. WRC-27 Agenda Item 1.7 studies are already contentious, with some stakeholders viewing the agenda as motivated largely by Chinese interests.
These systems all differ widely in propagation needs, mobility, operational tempo, installed base, and integration with larger mission systems.
This context is not intended to suggest a prohibition against, or very limited, U.S. commercial use. Instead, it suggests that a simplistic “clear and auction” narrative should not be pursued without careful and thoughtful consideration of less invasive alternatives. In other words, why use a blunt axe as a tool when a scalpel can do the job and cause less damage?
If American policymakers want a realistic and timely pathway for this band, now is the right time for NTIA and other federal agencies to work with industry on a proper evaluation of coexistence approaches in the 4 GHz band. They can create a win-win-win for federal incumbent operations, new commercial users, and U.S. global leadership in next-generation wireless systems and intelligent spectrum administration.
Other markets are already using 4GHz sharing models
A number of other global markets are already using the 4GHz band for shared and localized commercial use, based on a variety of mechanisms for protecting or coexisting with incumbents, and managing risks of interference.
- Japan provides “local 5G” licenses in the 4.6-4.9GHz range[1], used for various applications by enterprises and local governments. Deployments are subject to constraints such as power levels, preference for indoor-only / low-power use, and inter-site coordination. Japan also has some public 5G network usage in 4.5-4.6GHz, which was administratively assigned, not auctioned – and which also has various specific operational and coexistence conditions.
- Taiwan[2] allows indoor use for private, low-power 5G in the 4.8-4.9GHz range, with some limited outdoor use subject to cross-agency coordination. The main policy objective has been enablement of key verticals, such as semiconductor manufacturing.
- South Korea[3] allows use of 4.72-4.82GHz for private 5G networks in enterprises. It is subject to coordination and synchronization between neighboring sites.
The only place that has auctioned spectrum in the 4GHz band for exclusive use is Hong Kong, which assigned 80MHz of spectrum in the 4.84-4.92GHz range in 2019, subject to restriction zones around incumbent satellite installation. Mainland China has also allocated some of the top end of the band to MNOs, but it is subject to coordination and protection rules for incumbent users, and does not appear to have been widely deployed and utilized yet.
It is important to note that the 5G device and chipset ecosystem for this spectrum range (part of 3GPP’s band n79) remains limited, especially in mainstream smartphones.
Future 5G and 6G will use spectrum in different ways to today’s networks
The real growth opportunity for 5G and 6G is not “more of the same” nationwide, high-power macro coverage. Instead, it is more granular and use-case driven; it is more local, more dynamic, and often more domain-specific, with different implications for spectrum access.
Some of the potential growth categories include:
- Local private networks for industrial sites such as ports, logistics hubs and mines
- Indoor-optimised networks for venues, public buildings, and commercial real-estate
- “Corridor” networks for road, rail, utilities and power-lines
- Aerial connectivity for “drone highways” and the broader “low altitude economy”
- Federal and military use of their own tailored 5G/6G networks for bases, ranges, ports, and expeditionary use
- Temporary and “pop-up” 6G networks for events, disaster relief and surge capacity..
- Private networks relating to AI infrastructure build-out, such as datacenter campuses, new power and energy sources, semiconductor factories etc.
All of these use-cases will use spectrum, but often in very different ways to historical mobile carriers’ high power “macro” outdoor networks. There is a need for more granularity in the size, power and duration of licenses – and how they interact with neighbours and other spectrum users to maximize usefulness and minimize interference.
That naturally pushes the market toward fine-tuned licensing models like sharing that can express “rights” in finer detail: how much spectrum, where, when, and under what technical constraints. There will be more emphasis on directional control, synchronization, and coordination with neighbors and remaining incumbents.
In addition, 6G is expected to incorporate new sensing functionality. Much of the discussion is around radar-like awareness, using the wireless signals themselves. This is often described as ISAC, Integrated Sensing and Communications. This is still in very early stages of development and commercialization, but it may also focus on localized uses, such as drone-detection near sensitive sites.
In addition, as well as radar-type sensing, we can expect 6G-era networks to embed “spectrum-sensing” directly. The radio should be able to spot both unused bands (and perhaps request opportunistic use of lightly-occupied bands), and also detect and mitigate unexpected interference and anomalies.
In other words, 6G will likely need access to additional spectrum – but only in certain places and certain times. In other instances, new efficiencies or usage patterns suggest that 6G could need less spectrum than 5G. In particular, the addition of AI capabilities in 6G radio networks, and in the control and application domains, should allow much greater optimization.[4]
When the 4GHz range is examined through this lens, a key part of the puzzle could be solved by “intelligent coexistence” of 6G with incumbent and other new Federal spectrum users.
New models of sharing for the 4GHz band
Sharing can take many . Depending on the number of incumbent users and their diversity in needs, one model might fit better than others. Potential sharing approaches to be considered in isolation, or in combination with each other, include:
1) Time-based sharing
- Priority windows for test and training exercises
- Pre-emption rights for emergency response, contingency operations, and surge events
- Event scheduling coordinated via a trusted authorization service or database
2) Location-based sharing
- Geofenced protection zones around sensitive Federal facilities, ranges, ports, and also commercial satellite and radio-astronomy sites
- Differentiated rules by region (dense urban enterprise use vs. rural vs. restricted military corridors)
- Licensing models that match actual use cases (campus, venue, industrial, municipal, linear corridors etc.)
3) Directional and technical sharing
- Beamforming constraints and power masks to protect specific incumbent links
- Synchronization requirements for TDD coexistence with neighbors and incumbents
- Mandatory coordination for outdoor deployments
- Device certification profiles tuned for local deployments
4) Authorization and coordination mechanisms
There are various approaches possible, as well as hybrids. Specific 4GHz sub-bands may work better with some models rather than others, given the nature of incumbents and their sensitivity / security constraints.
- Database-driven coordination, like an evolved version of the 6GHz AFC, with grants based on incumbent registries and propagation models
- Managed local licensing, with defined technical rules and coordination obligations
- Dynamic models incorporating realtime sensing and a CBRS SAS-type grants, potentially just in certain locations where the costs and complexity is justified.
The important point is that none of these require treating the band as a binary choice between “fully cleared nationwide macro IMT” and “no commercial use at all”. Given the finite resource of spectrum, existing incumbent operations and the potential for disruption that heavy-handed clearance approach could have, policymakers ought to properly “kick the tires” on a variety of spectrum-sharing models, before resorting to more disruptive approaches.
Conclusions
In the wake of the OBBBA, some industry advocates have doubled-down on the “clear and auction” approach as the only way to reach a vibrant 6G vision. However, the actual needs of our 6G future, along with the proven success of spectrum sharing and its efficiency, should cause policymakers to fairly and carefully consider viable options for coexistence or other models of flexible licensing, especially where incumbent users are difficult or overly expensive to clear.
If new spectrum is being considered for commercial use, policymakers should not reflexively assume it must be allocated for exclusive licensing for mobile carriers. Some bands are better suited to sharing and local licensing models that maximize usefulness while minimizing interference and relocation risk. The likely 6G use-cases further nudge in that direction.
With its myriad of incumbent government uses, the 4.4–4.9GHz band is especially worthy of serious examination through a sharing lens. It would be a missed opportunity – and not genuinely innovative – to treat it as just another source of “old-school,” high-power, nationwide exclusive licensed spectrum.
There is at least as much innovation potential for the United States in the mechanisms of coexistence and sharing – databases, coordination, sensing, security-aware authorization, and AI-enabled spectrum intelligence – as there is in providing “more of the same” spectrum for conventional mobile broadband.
Sharing in the 4GHz band may not be the only choice, or even the best choice in every segment of the band. But a shared-spectrum approach should be thoroughly examined and stress-tested, rather than dismissed in favor of clearance by default.
The history and success of CBRS and the emergence of localized private 5G frameworks have debunked the notion that sharing is a fringe idea. The 4GHz band is a strong candidate for applying that tool thoughtfully, with U.S. innovation leadership as a core objective.
[1] https://www.netmanias.com/en/post/blog/16282/5g-private-5g/japan-s-private-5g-deployments-sub-6-vs-millimeter-wave
[2] https://www.digitimes.com/news/a20251016PD214/taiwan-5g-o-ran-moda-itri.html
[3] https://www.netmanias.com/en/post/oneshot/15751/5g-private-5g/private-5g-deployment-status-in-korea-updated-2025-09-18[4] https://broadbandbreakfast.com/dean-bubley-winning-in-6g-will-not-require-more-spectrum/
Dean Bubley is the founder of Disruptive Analysis. He is an independent technology industry analyst, futurist, speaker and advisor, with over 25 years’ experience. He specialises in wireless, telecoms and policy fields. 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.
