The final hurdle was removed by the FCC as it certified four Spectrum Access System (SAS) administrators, paving the way for full commercial operations in the 3.5 GHz band, according to Public Notice DA 20-110. OnGo Networks using Citizens Broadband Radio Service spectrum can be deployed anywhere in the country now. Previously, OnGo networks could only be deployed far from the coasts under an order known as the Initial Commercial Deployment, a transitional phase that allowed the FCC to further vet the effectiveness of the SAS administrators.
To ensure that the Department of Defense (DOD) has continued access to the band for its Navy radar, Environmental Sensing Capability (ESC) networks were set up along the U.S. coast. The ESC networks inform the SAS administrators — CommScope, Federated Wireless, and Google — to activate a protection zone and dynamically reassign users in the area to other parts of the band, when the radar systems are activated.
The Dynamic Spectrum Alliance (DSA) said that dynamic spectrum sharing, also known as automatic frequency coordination, will not only make CBRS possible in the 3.5 GHz band but also the use of 5G in other bands.
“As we automate frequency coordination and, thereby, lower transaction costs, use spectrum more efficiently, speed time to market, protect incumbents from interference with certainty, and generally expand the supply of wireless connectivity that is fast becoming, like electricity, a critical input for most other industries and economic activity,” DSA said in a white paper.
The FCC is considering using automatic frequency coordination to facilitate shared access by unlicensed, licensed and lightly-licensed users in such bands as: 6 GHz, 3.7-4.2 GHz and 37-37.6 GHz.
The evolution of automated frequency coordination is not over. DSA’s report discusses emerging technology that may benefit AFC systems, such as real-world GIS data (e.g., terrain, clutter, building heights and materials); real-time spectrum sensing data; sophisticated propagation and interference modeling; cloud-based database services; and blockchain technology.
Political Cooperation a Necessity for CBRS
As well as latest technology, the CBRS initiative involved public/private partnerships between industry and government organizations. Federal agencies including the FCC, National Telecommunications and Information Administration (NTIA), Institute for Telecommunication Sciences (ITS), and Department of Defense, along with the Wireless Innovation Forum and the 159 members of the CBRS Alliance.
“NTIA’s groundbreaking engineering work and close collaboration with the FCC, DOD and industry played a critical role in opening up the 3.5 GHz CBRS band for next-generation wireless services,” said Douglas Kinkoph of the NTIA.
Prior to commercial availability, the 3.5 GHz CBRS band was used primarily by the DoD, mostly for shipborne radar systems. The ESC networks inform the SAS administrators to activate a protection zone and dynamically reassign users in the area to other parts of the band, thus protecting the incumbent’s use of the spectrum while maximizing availability of CBRS spectrum across coastal areas.
“The authorization of full commercial deployments in the CBRS band is a significant milestone in our nation’s management and utilization of a vital resource, the radio frequency spectrum,” said Dana Deasy, Chief Information Officer for the DoD. “The Defense Department worked closely with our federal partners at the NTIA and FCC, and with industry, to ensure that our mission critical operations would be protected while enabling new commercial uses. Collectively, we were able to creatively address the engineering and security challenges associated with military and commercial spectrum sharing. We look to build upon those successes going forward. Additionally, I would like to thank the men and women in DoD who have diligently worked to make today possible.”