Behind the Scenes: How We Built a Test Environment That Accelerated CBRS Innovation

By Jesse Caulfield, CEO, Key Bridge Wireless LLC
January 19, 2026

Innovation in shared spectrum doesn’t happen in production—it happens in safe, realistic sandboxes where vendors, integrators, and operators can push boundaries without risk.

Over the last five years, one of the most impactful (yet least visible) parts of Key Bridge’s contribution to the CBRS ecosystem has been our dedicated test SAS environment. It’s where hundreds of interoperability tests, new feature validations, and vendor certifications have taken place—quietly accelerating the pace of innovation that brought us to more than 400,000 deployed CBSDs today.

Looking back as we start 2026, I wanted to pull the curtain on how we designed and evolved this environment, and why it became a key enabler for the industry.

The Early Challenge

When Key Bridge first earned FCC certification in 2020–2021, the CBRS ecosystem was still young. Vendors needed to prove their CBSDs and Domain Proxies could talk correctly to a SAS, handle edge cases like grant terminations, and respond to simulated incumbent activity.

But production environments aren’t the place for experimentation. A misconfigured test could trigger real suspensions, waste valuable spectrum, or create compliance headaches.

We knew from day one that a robust, isolated test SAS was essential—not just for our own development, but for every partner and customer building on the platform.

Designing for Realism and Flexibility

From the beginning, we took a different approach than many expected:

• Full protocol fidelity — The test environment implements the complete WinnForum SAS-CBSD specification (registration, inquiry, grant, heartbeat, relinquishment, deregistration) with the same message formats and response codes as production.
• Realistic protection simulation — We built in persistent and on-demand Dynamic Protection Areas (DPAs), a fixed Grandfathered Wireless Protection Zone (GWPZ) in the 3650–3700 MHz range, and emulated ESC sensor triggers. This lets testers experience genuine grant terminations and power reductions without affecting real incumbents.
• Maximum flexibility on certificates — One of the most appreciated features: you can use either your production certificates (completely harmless in the isolated test environment) or request dedicated test certificates from us. Both are fully supported, making onboarding fast for everyone from large vendors to small integrators.
• Complete isolation — No data, grants, or configurations ever cross into production. Test User IDs are separate, and the environment resets cleanly.

The Impact on Innovation

The results spoke for themselves:

• Vendors could iterate rapidly—running full test suites in hours instead of days of coordinated scheduling.
• New features (like advanced channel guidance and multi-PAL aggregation) were validated long before production rollout.
• Training and proof-of-concept work became frictionless—teams could spin up realistic scenarios without waiting for approval cycles.
• Interoperability improved across the board as edge cases were caught and fixed early.

In an ecosystem that added tens of thousands of CBSDs in 2025 alone, this kind of accelerated, low-risk testing was critical to maintaining momentum.

Why It Matters Now More Than Ever

As we cross into 2026, CBRS is no longer experimental. Enterprises demand carrier-grade reliability. Private 5G networks are business-critical. Neutral hosts and rural providers operate at scale.

That means the bar for quality and interoperability is higher than ever. A robust test environment isn’t a luxury—it’s table stakes for continued innovation.

At Key Bridge, we continue to invest in this capability because we believe the fastest way to advance the ecosystem is to make safe, realistic testing accessible to everyone.

Try It Yourself

Whether you’re certifying a new CBSD model, integrating a Domain Proxy, or just exploring CBRS for the first time, our test environment is open and ready.

Reach out to support@keybridgewireless.com for access, test certificates, or guided sessions. We’re here to help you innovate faster—and with confidence.

Here’s to the unsung infrastructure that powers progress.

Best regards,
Jesse Caulfield
CEO, Key Bridge Wireless LLC
McLean, Virginia

Key Bridge Wireless – Automated Spectrum Access for a Connected World