The Citizens Broadband Radio Service, better known as CBRS, has often been described as an experiment in spectrum sharing. Based on the latest OnGo Alliance webinar on the state of CBRS, that description no longer feels accurate. CBRS is now a sizeable and maturing wireless ecosystem in the United States, supporting mobile operators, cable companies, wireless internet service providers, private network deployments, neutral host systems and a growing range of enterprise use cases.
For those less familiar with CBRS, it operates in the 3.5 GHz band in the United States and uses a shared spectrum framework. Rather than relying only on traditional exclusive licensing or completely unlicensed access, CBRS introduced a three-tier model, coordinated through a Spectrum Access System, or SAS. This software-based coordination layer allows different users to access spectrum while protecting incumbent users, including government and defence systems.
The model has taken more than a decade to develop. The discussion began around 2012, when US policymakers and defence stakeholders started exploring whether mid-band spectrum could be shared more efficiently between government and commercial users. The first FCC rule and order arrived in 2015, followed by the creation of the OnGo Alliance in 2016. The role of the Alliance was to bring together government, industry, technology providers and users to translate the regulatory framework into a workable commercial ecosystem.
A key point from the webinar was that CBRS has not developed as a single-sector technology. It is not just for mobile operators, and it is not just for private wireless. It brings together mobile network operators, cable companies, WISPs, system integrators, RAN vendors, device manufacturers, SAS administrators, enterprises, airports, campuses, healthcare facilities, utilities and many others. This diversity is one of the main reasons CBRS has become interesting from a broader telecoms perspective.
The scale of deployment is now significant. The webinar highlighted more than 437,000 CBRS devices deployed across the United States, more than 1,000 CBRS operators and networks, around 1,100 certified end-user devices supporting Band 48, and more than 1,800 private network deployments. The total ecosystem investment was described as being more than 14 billion US dollars, including spectrum, equipment, standardisation, technology development, SAS infrastructure and sensing networks.
The Priority Access Licence, or PAL, auction also played an important role. Auction 105 raised close to 5 billion US dollars and created around 22,000 PAL licences. Unlike some traditional spectrum auctions, the county-based licence areas allowed smaller and regional players to participate, particularly in rural and suburban markets. This is important because CBRS has become a practical tool not only for national-scale operators but also for smaller service providers addressing local connectivity needs.
One of the most useful ways to understand CBRS is to place it between two familiar models. On one side there is unlicensed spectrum, mainly associated with Wi-Fi, which is easy to access but can suffer from congestion and unpredictability. On the other side there is exclusive licensed spectrum, which provides stronger control but is expensive, complex and usually held by major operators. CBRS sits between these models. General Authorised Access, or GAA, provides licence-by-rule access, while PAL provides a higher-priority licensed layer. The SAS coordinates access and helps manage coexistence.
This software-managed spectrum access model is one of the most important aspects of CBRS. In a traditional licensing model, gaining access to spectrum can be slow and expensive. In CBRS, the SAS can authorise spectrum use in minutes. The network operator interacts with the SAS, while the end user does not need to know that this process is happening. In many deployments, even the radio does not need to communicate directly with the SAS because a domain proxy or network management system can handle that interaction.
The webinar also made clear that CBRS is evolving. CBRS 2.0, introduced in 2024, expanded availability by refining the way incumbent protection is handled. This opened the band to an additional 72 million Americans, mainly through software and regulatory improvements rather than any major change in physical infrastructure. That is a powerful example of how shared spectrum systems can improve over time as data, models and operational experience mature.
Fixed Wireless Access is one of the most visible CBRS use cases. WISPs and FWA providers are using CBRS to serve suburban, rural and ultra-rural communities, often in places where connectivity options are limited. The webinar suggested that CBRS-based WISPs and FWA providers are serving more than 10 million residential customers in the United States, with many of these customers located in areas that have fewer than two viable internet options.
This is a useful reminder that wireless and fibre should not always be seen as competing technologies. In many rural deployments, CBRS is used as part of a hybrid model, with fibre providing backhaul and fixed wireless covering the final stretch. This can be faster and cheaper than extending fibre everywhere, particularly in difficult terrain or sparsely populated areas. It can also be more resilient in emergencies, as wireless networks can often be restored more quickly after fires, floods or other disasters.
The discussion also touched on competition from low Earth orbit satellite systems such as Starlink and future Amazon Kuiper services. The speakers framed satellite and CBRS-based FWA more as complementary technologies than direct competitors. This is a sensible view. Rural broadband is not a single-problem market. Some locations will be better served by terrestrial fixed wireless, some by fibre, some by satellite, and many by a combination of these approaches. The real value comes from having multiple options.
Private networks are another major part of the CBRS story. Enterprises can use CBRS spectrum for their own dedicated cellular networks, with applications tailored to their operational needs. These networks can sit inside the enterprise firewall and support predictable performance, mobility and security. Typical applications include point-of-sale terminals, push-to-talk communications, video surveillance, automated guided vehicles, warehouse systems, robotics, utilities, airports, ports, rail yards and industrial facilities.
The mobility angle is especially important. Wi-Fi is excellent for many indoor and enterprise use cases, but private cellular can provide more predictable mobility, coverage and quality of service in large sites, outdoor environments and industrial locations. As physical AI, robotics and autonomous systems become more widely deployed, reliable wireless connectivity will become more important. CBRS gives enterprises in the United States a practical route to deploy private cellular without needing to own exclusive nationwide spectrum.
Neutral host networks were also highlighted as a major growth area. In this model, an enterprise, venue or building owner deploys CBRS-based infrastructure to improve indoor mobile coverage for users of public mobile networks. This can help solve the common problem of poor indoor mobile signal, dropped calls and dead zones, especially in buildings where a traditional distributed antenna system is too expensive or too difficult to justify.
The safety aspect of neutral host coverage deserves more attention. Buildings often have public safety communications requirements for first responders, but the ability of occupants to call emergency services from inside the building is just as important. A neutral host system integrated with mobile operators can support emergency calling and wireless emergency alerts. This makes indoor cellular coverage not just a convenience issue but a safety and resilience issue.
The webinar suggested that around 80% of buildings in the United States lack adequate mobile coverage. While this figure may vary depending on building type and methodology, the underlying point is easy to recognise. Many offices, schools, hospitals, hotels, warehouses and public buildings still have patchy indoor mobile coverage. CBRS-based neutral host systems could lower the barrier for improving this, especially in mid-sized buildings that would not previously have justified a traditional operator-led solution.
Several verticals were identified as having strong growth potential. Airports are already emerging as a good example, with CBRS supporting operational communications, asset tracking, baggage handling and other behind-the-scenes functions. Ports, shipyards, utilities, factories, schools, campuses, hospitals, tribal communities, hospitality venues, stadiums and public sector facilities were also mentioned as areas where CBRS can support either private networks, neutral host networks or both.
Smart agriculture is another interesting opportunity. Farms often have poor mobile coverage but growing connectivity needs, from precision agriculture and sensors to equipment monitoring and automation. CBRS could provide localised, high-quality coverage where traditional mobile networks are weak or unavailable. Healthcare was also mentioned as a sector with significant potential, particularly as hospitals still rely on a mix of legacy communications tools while demanding more reliable mobile and telemetry connectivity.
One of the more forward-looking points came near the end of the webinar, where CBRS was positioned as a good candidate for AI-enhanced spectrum management. Because CBRS relies heavily on software, propagation models, measurements, databases and SAS-based decision-making, it creates an environment where AI could potentially improve spectrum availability and interference management. This will require careful regulatory support, but the idea is important. Spectrum sharing should not be static. It should improve as better data and better models become available.
The broader lesson from CBRS is that shared spectrum can work when the technical, regulatory and commercial models are aligned. It has created a middle ground between unlicensed and exclusive licensed spectrum. It has enabled smaller operators and enterprises to access mid-band spectrum. It has supported rural broadband, private networks and neutral host systems. It has also shown that incumbent protection and commercial deployment do not have to be mutually exclusive.
There are still challenges. Regulatory uncertainty remains a concern, especially if potential investors or deployers worry that the rules could change. Further refinements will be needed around incumbent protection, antenna heights, fixed satellite protection, indoor systems, distributed antenna systems and future enhancements. However, the direction of travel is positive. CBRS is no longer just a policy experiment or a niche wireless band. It is becoming an important part of the US connectivity landscape.
For markets outside the United States, CBRS is worth watching because it offers a real-world example of dynamic spectrum sharing at scale. Not every country will copy the CBRS model directly, and spectrum availability, incumbent use and regulatory priorities will differ. Even so, the principles are relevant. As demand for mid-band spectrum grows, governments and regulators will need more flexible ways to balance public, private, commercial and national security needs. CBRS shows one way this can be done.
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