Commenters Disagree on Carrier-Proposed Rule Changes for CBRS Band

The FCC got dozens of comments on an August NPRM from wireless carriers, tech companies and others on further changes to rules for the citizens broadband radio service band (see 2408160031). In filings posted through Thursday in docket 17-258, commenters disagreed sharply on a proposal by carriers to more closely harmonize CBRS rules with those for the adjacent 3.45 GHz and C-band.

The FCC adopted initial CBRS rules in 2015, creating a three-tier model for sharing 3.5 GHz spectrum, while protecting naval radars. In July, changes kicked in that loosened restrictions on the band, which are expected to spur additional use (see 2407250039). The NPRM explores further rules changes (see 2406130055).

CTIA supported proposed changes to the CBRS coordination and sharing framework developed through collaboration between federal agencies and industry. “These changes have helped pare back some of the overly conservative protections that were a result of worst-case assumptions baked into the CBRS modeling and measurements, which contributed to the band’s underutilization,” the group said.

The FCC should also adopt proposals eliminating "unnecessary regulations that have been overcome by events,” especially out-of-band emissions requirements for the adjacent C-band, CTIA said. “Refrain from adopting” proposals to set aside general authorized access tier spectrum for indoor deployments, the group said: “Wireless providers and vendors are deploying private and indoor wireless use cases today using not just CBRS spectrum, but a wide variety of licensed and unlicensed spectrum bands as well.”

AT&T reiterated advocacy for changes in how 3 GHz, including CBRS, is configured (see 2410090037). “This proceeding offers the Commission a unique opportunity to incorporate the 3.5 GHz spectrum into a broader, rationalized 3 GHz band with harmonized technical service rules,” AT&T said.

EchoStar urged a national time-division duplexing synchronization framework, new categories of higher-power CBRS base stations, higher power limits for end-user devices, relaxed in-band and out-of-band emission limits and harmonized emission limits across adjacent spectrum bands. “Since the Commission adopted these rules, the rest of the globe has recognized the important role this band can plan in 5G deployments,” EchoStar said.

"U.S. wireless leadership depends on making more mid-band spectrum available,” emailed Jeff Blum, EchoStar executive vice president-external and government affairs: “Aligning CBRS power levels, synchronization, and emissions requirements with international standards would reduce barriers to technology deployment, streamline costs, and enable network operators to bring new 5G and 6G services to market faster.”

NCTA, public interest groups and others opposed changes the wireless industry proposed.

Given the positive momentum behind CBRS, it’s “troubling that some parties have proposed fundamental alterations to the CBRS framework, including higher transmit power levels for outdoor base … and relaxed in-band emissions limits,” said NCTA: “If adopted, these changes would impair existing small-cell deployments and frustrate new small-cell deployments, even while demand for mobile data services grows increasingly concentrated in discrete local areas, making small-cell architectures essential to ensuring that networks can meet this demand.”

The FCC must resist “a push by some incumbents to remake the band into a traditional band customized for specific purposes like mobile carrier 5G,” the Public Interest Spectrum Coalition said. “To do so would be to take a step backward to the old days of ‘command and control’ by effectively limiting use to a single business model through technical rules rather than explicit regulation.” The Open Technology Institute at New America and Public Knowledge led the filing.

Spectrum for the Future opposed higher power levels in the band. “In addition to reducing the number of potential users and licensees able to coexist in the band, raising power levels and out of band emissions limits has the potential to generate additional adjacent-channel interference, unnecessarily complicating and threatening existing CBRS uses,” the group said.

The Competitive Carriers Association said CBRS can be helpful in bringing wireless coverage to rural markets. “Working towards enabling additional commercial wireless use at increased power levels would not only prove beneficial for smaller and rural carriers that comprise the bulk of CCA’s members by lowering the cost of deployment, but also simplify coexistence in the mid-band range” between the higher-power 3.45 GHz and C-band spectrum, the group said. The FCC must “balance the benefits of higher power against the costs of observing more demanding OOBE limits,” CCA said. But in the view of CCA members, “the benefits of higher power generally outweigh the costs of more stringent OOBE limits.”

John Deere called for a class of CBRS devices for rural areas “with power limits the same as those found in the 3.45 GHz and 3.7 GHz bands.” The FCC should “look at ways of harmonizing the rules for the CBRS band with the 3.45 GHz and 3.7 GHz bands in rural areas, where capital for widespread infrastructure investment is scarce and coverage -- not capacity -- is the primary motivation for CBRS deployment,” Deere said: “Harmonizing the rules for these bands should reduce the cost of expected deployment for the Commission’s upcoming 5G Fund, stretching scarce federal dollars further to bring 5G to those without it today.”

T-Mobile said the FCC should gather data and move carefully on rules changes for the spectrum. Following further review, “the Commission should carefully consider the costs and benefits of making significant technical changes,” T-Mobile said: “Increased power levels, altered [OOBE] limits, and greater antenna heights, as well as related service rule changes, could potentially disrupt the operating environment, exacerbate interference under the current band plan, and undermine the policy considerations underlying the band.”