What is 3.5GHz Citizens Broadband Radio Service?
As part of former President Obama national initiative to develop and promote next generation of wireless networks (commonly referred to as “5G networks”), on April 17, 2015 , the Federal Communication Committee (FCC) adopted a
Report and Order and Second Further Notice of Proposed Rulemaking (3.5 GHz Order) that established a new Citizens Broadband Radio Service (CBRS) for shared wireless broadband use of the 3550-3700 MHz band (3.5 GHz CBRS Band). Essentially this is the first unlicensed wireless spectrum to become available in US in the last decade, allowing growth of innovation in multiple fields.
“The 3.5 GHz band is an innovation band. As a result of technological innovations and new focus on spectrum sharing, we can combine it with adjacent spectrum to create a 150 megahertz contiguous band previously unavailable for commercial uses. It provides an opportunity to try new innovations in spectrum licensing and access schemes to meet the needs of a multiplicity of users, simultaneously. And, crucially, we can do all of this in a way that does not harm important federal missions.”
– Tom Wheeler, FCC chairman
Why is CBRS of so important?
Wireless connectivity has become increasingly important in our everyday life. It is widely used for work, play, and learn by everyone we know.
However, today the wireless communication faces several challenges:
- Cost of broadband spectrum is extremely high
- Rural Areas are underserved, preventing large portions of US population from fully taking advantage of all services and innovations.
- Emergency services are not available in many areas
- Rollout of 5G networks are hampered by inadequate spectrum
The new CBRS technology will create additional spectrum available for flexible wireless broadband use, leading to improved broadband access and performance for consumers. Additionally, I expect to see wide deployment of wireless broadband in industrial applications – advanced manufacturing, energy, healthcare, etc. – supporting innovation and growth throughout our economy.
Several examples of benefits are:
- Better Internet Access to users in urban and rural areas:
- Cellular coverage in previously unserviceable locations (basements, office buildings, etc):
- Private LTE networks:
- Industrial IoT innovation:
The 3.5 GHz band is an innovation band. As a result of technological innovations and new focus on spectrum sharing, we can combine it with adjacent spectrum to create a 150 megahertz contiguous band previously unavailable for commercial uses. It provides an opportunity to try new innovations in spectrum licensing and access schemes to meet the needs of a multiplicity of users, simultaneously. And, crucially, we can do all of this in a way that does not harm important federal missions.
The draft Report and Order implements a three-tiered sharing paradigm, which we have explored in multiple rounds of notice and comment over the past two years. The lowest tier in the hierarchy, General Authorized Access (GAA), is open to anyone with an FCC-certified device. Much like unlicensed bands, GAA will provide for zero-cost access to the spectrum by commercial broadband users. In the Priority Access tier, users of the band can acquire at auction targeted, short-duration licenses that provide interference protection from GAA users. Finally, at the top of the hierarchy, incumbent federal and commercial radar, satellite, and other users will receive protection from all Citizens Broadband Service users.
This new tiered sharing paradigm will be enabled by a Spectrum Access System. The SAS takes an age-old role in spectrum management – the frequency coordinator – and updates it for the 21st century through the use of cloud computing technology. Long gone are the days of an engineer working with pencil and protractor (not to mention pocket protector) to coordinate users into a band.
Finally – a few words on protecting incumbent federal uses. America’s military uses this band for radar systems that perform vital national security missions. To protect these radars, previous reports suggested very large zones around the coasts within which commercial users could not operate. Thanks to an enormous amount of collaborative work with NTIA and the Department of Defense, these zones are now substantially smaller. More importantly, the draft Report and Order provides a roadmap, recommended by NTIA and DoD, for operations within any area around the coast through the use of new sensor technologies.
