The CBRS band will open up LTE opportunities to a more diverse group of providers rather than just the wireless and fixed telecom companies. Cable companies and others will be able to develop, build and operate their own wireless networks, bypassing the “Big 4” mobile operators. Opening up this previously protected spectrum will pave the way for providers to deploy 5G networks without having to acquire the traditional spectrum licenses.

How CBRS Spectrum will be managed

CBRS is set up to create wide access to much-needed mid-band spectrum, which is well-suited for 5G because of its balance between distance and speed. The FCC Rules define three levels of access in descending order for assigning access to the CBRS spectrum.  

Tier 1 – Incumbent Access

Incumbent Access users include federal government users, fixed satellite services (space-to-Earth stations), and grandfathered wireless broadband licensees in the 3650-3700 MHz band. These first-tier users, particularly the US Navy radar operators and the DoD will be protected against harmful interference from the users in the second and third tiers of Priority Access and General Authorized Access. The grandfathered WISPs occupying the band will eventually need to switch to one of the other tiers once their licenses expire, but no earlier than October 17, 2020.

Tier 2 – Priority Access Licenses

The Priority Access Licenses (PAL) will be licensed on a county-by-county basis through a competitive bidding process. Spectrum in the      PAL tier consists of 10 megahertz channels within the lower 100 MHz of the band. Those in the PAL tier will get a ten-year renewable license with up to 40 MHz of spectrum going to any single applicant. While there are no interim service milestones to be met, PALs are required to meet a substantial performance requirement by the end of the initial term and must ensure protection from interference for the Tier 1 Incumbents. PALs will, however, receive protection from the third tier, the General Authorized Access users.

Tier 3 – General Authorized Access

The General Authorized Access (GAA) tier permits open, variable access for a wide group of possible users. GAA users can use any portion of the 3550-3700MHz band that is not assigned to a higher tier user. Another advantage is that these users may also operate, when they are available, on any unused Priority Access channels. GAA users must still restrict their use to be sure they do not cause harmful interference to Incumbent Access or Priority Access users. Conversely, GAA users must accept interference from the incumbents and Priority users. As the lower Tier, the GAA users will not have any protection from interference from other GAA users; however, the SAS will regulate use among the unlicensed GAA users.

 Advantages of CBRS

The CBRS unquestionably opens the door for non-traditional wireless carriers to build their own network. Cable operators are seeing opportunities for CBRS in home settings as LTE’s quality and security allows cable providers to transition WiFi routers into CBRS-compatible gateways. By combining the best of both the LTE and Wi-Fi networks, the GAA private networks can offer traffic management, security, and reliability along with low latency.

And licensees could potentially move smart home devices to run on CBRS networks. Companies like Amazon, Google and many industrial enterprises want to use the spectrum to build LTE and later 5G private networks for IoT and other applications. Amazon has tested a private IoT network to support devices such as real-time surveillance cameras and smart meters. Comcast and Charter are also eyeing opportunities for private networks.

Although there is tremendous interest in using the band, ultimately, its success will depend on a number of factors. Top of the list, however, will be the ability of the sharing system to protect the access of Tier 1 incumbent users, especially the US Navy. Although multiple trials have taken place, it will take some time to determine whether spectrum sharing works as envisioned.

The filing window for the FCC's CBRS auction starts April 23, 2020, with bidding beginning on July 23, 2020. 

For a more detailed look at the CBRS band and licensing be sure and watch our Tech Tuesday broadcast: CBRS Spectrum: What is it and how will it be used?