Citizens Broadband Radio Service (CBRS)

Making More Efficient Use of Mid-Band Spectrum

U.S. wireless leadership depends on using available mid-band spectrum more efficiently. One underutilized block is the Citizens Broadband Radio Service (CBRS) located between 3.55 GHz and 3.7 GHz. The Federal Communications Commission (FCC) has an active Notice of Proposed Rulemaking (NPRM) where they are soliciting feedback to improve the band, including the possibility of higher power levels.

 

The FCC launched the CBRS band’s rules in 2015 with an innovative three-tiered licensing regime to manage use between existing government users, new commercial licensees, and the general public. These new license types were named Incumbent Access, Priority Access License (PAL), and General Authorized Access (GAA), with each level receiving decreasing levels of protection from harmful interference. 

 

Designing the CBRS band to support sharing allowed the Commission to repurpose a large swath of mid-band spectrum to accommodate new uses for wireless providers, while still preserving the band for critical federal government and military users. The key innovation is an automated frequency coordinator, known as a Spectrum Access System (SAS), which dynamically allocates available spectrum in the band and communicates when a user must halt operations to avoid interference with another, higher-tier licensee.

 

Though the CBRS band’s unique structure still holds promise, subsequent decisions by the FCC to approve higher-power service in neighboring 3 GHz spectrum bands (3.45 GHz and 3.7 to  4.2 GHz/C-band) have disadvantaged U.S. wireless operators against global peers. As EchoStar wrote in its comment on the NPRM, the current CBRS framework makes it “harder for American companies to deploy comprehensive, cost-effective mobile 5G networks in the CBRS band and prevents a seamless 5G solution across the broader 3.45-3.98 GHz band (“3 GHz band”). As a result, today’s rules threaten to harm U.S. leadership in 5G technology and the public interest.”

 

Protecting CBRS’s Unique Structure

 

EchoStar and other advocates have proposed aligning CBRS standards more closely with global rules for the 3 GHz band to enable wireless providers to deploy the same radios, devices, and base stations across markets. Providers could then cover more users with fewer towers, reducing expenses and benefiting customers with better coverage, all while protecting other CBRS incumbents from harmful interference.

 

Importantly, unlike other proposals to modify the band, EchoStar’s proposed changes would preserve the innovative sharing structure of CBRS. Extensive third-party technical analysis demonstrates the proposed updates would avoid harmful interference to other users.

 

EchoStar’s Proposals to Improve CBRS

 

EchoStar has submitted five core suggestions for improving the CBRS band. They include:

  • A national time-division duplexing (TDD) synchronization framework;

  • New categories of higher-power CBRS base stations (CBSDs);

  • Higher power limits for end-user devices;

  • Relaxed in-band and out-of-band emission limits; and

  • Harmonized emission limits across neighboring spectrum bands. 

 

The net effect of these specific proposals would be allowing PAL licensees to use the band at higher power levels that are aligned with neighboring bands and with global standards for wireless transmissions in the 3 GHz frequencies. It would also open opportunities for network operators to use CBRS licenses to supplement their existing networks in areas that are not likely to see Incumbent Access use (i.e. military operations). Better synchronization between uplink and downlink transmissions across the band would also allow operators to use the available spectrum more efficiently, reducing the need for guard bands or geographic separation to avoid interference.

 

Absent these changes, the CBRS band will be less effective for helping to connect Americans. Namely, transmissions will not be able to travel as far, requiring many more towers to cover the same number of users. Plus, providers will not be able to use the same radios and other equipment they use for other 3 GHz deployments because the equipment will need to be designed to broadcast at the much lower power levels and emissions that current CBRS rules require. Acquiring the dedicated equipment and achieving increased network density is expensive and significantly increases the cost for CBRS deployments in the U.S. It has already slowed deployments in the band. 

 

The FCC should move quickly to unlock the full potential of the CBRS band and support the future of U.S. wireless leadership.


For more background and information on EchoStar’s position, you may refer to our comprehensive filing on the CBRS NPRM with the FCC.