Concerns Raised Over FCC Plan for 3.5 GHz Band

Comments were due Wednesday on the notice (http://bit.ly/12Ruwzn). The FCC has also scheduled a workshop at its headquarters March 13 with various panels that will discuss the 3.5 GHz band.

The proposal is for the band be reallocated under a three-tiered “Citizens Broadband Service” under Part 95 of the commission’s rules (CD Dec 13 p6). The rules propose a priority access tier for use by hospitals, utilities, first responders and other entities with critical needs who would operate with some interference protections in parts of the band in designated areas. In a general access band, the public would be permitted to use the spectrum on an “opportunistic basis,” though their use would be subject to interference.

"The Commission recognizes that the 3.5 GHz Band holds great potential for small cell applications, but states that it is not ideal for exclusive licensed commercial mobile broadband uses,” said T-Mobile, which is widely viewed as the most spectrum-constrained among the major carriers. The FCC goes wrong in assuming that spectrum designated for small cells must be dedicated to unlicensed use, T-Mobile said (http://bit.ly/XALr42). “Licensed providers also need small cell capacity, and licensed spectrum designated for small cell operations can be effectively integrated into carriers’ networks,” the carrier said.

Carriers already “make extensive use” of unlicensed spectrum in the 2.4 GHz and 5 GHz bands, T-Mobile said. “T-Mobile has a long and proud history of using unlicensed spectrum,” the filing said. “While T-Mobile and other carriers use unlicensed spectrum today for offloading, it does not follow that all offload spectrum should be available on an unlicensed basis only. To the contrary, carriers can make even greater use of spectrum for broadband capacity if that spectrum is made available to them on an exclusive basis through licensing."

The Telecommunications Industry Association said the FCC should prepare a cost-benefit analysis of its three-tier proposal for the band before making any decisions on reallocating the spectrum. The FCC was too quick to reject licensed used of the spectrum, TIA added. “Exclusive licensed, flexible-use spectrum bands have proven utilization efficiency, adoption density, and well-established parties to sustainably deploy them,” the filing said (http://bit.ly/YDXkWi). “The Commission seems to reject this alternative simply because of comments filed (by AT&T and CTIA) in a Public Notice nearly 2 years ago. Those comments were interpreted out of context and were directed toward specific NTIA analysis results which included mobility, as well as large exclusion zones covering major population centers."

"We applaud the Commission’s effort to convert a very substantial but grossly underutilized swath of spectrum into an intensively-used small-cell band in a manner that not only protects military and other incumbent systems from interference, but also builds a foundation for more extensive private sector sharing of underutilized bands with an automated governing mechanism,” said PISC, which represents the Open Technology Institute at the New America Foundation, Consumer Federation of America, Public Knowledge and Free Press. But PISC said in a world of spiraling demand for data, the old model built around dedicated, licensed spectrum in the hands of carriers is no longer enough (http://bit.ly/YDW4Cl). “Hybrid and heterogeneous networks -- combining licensed and more short-range shared and/or unlicensed spectrum -- are the most feasible solution to the increased demand for video and other bandwidth-intensive applications on mobile devices,” PISC said. PISC also said the FCC should keep the rules for shared use of the 3.5 GHz band “as simple and flexible as possible” since “this will encourage standardization and mass deployment."

NAB raised concerns about potential interference to C-band satellite operations in the 3700-4200 MHz band. “This spectrum is used intensively by broadcasters, syndicators, cable networks and others to deliver most pre-recorded news, sports, public affairs and entertainment programming to local stations, and in turn, to audiences throughout the United States,” NAB said (http://bit.ly/Zu8CRQ). “The C-band is also used to distribute certain widely-viewed, pre-scheduled live programming, as shown by the C-band trucks located on-site at the Super Bowl and the Grammy Awards.” NCTA shared these C-band worries. “Assuming that interference to the 3.7-4.2 GHz bands can be avoided or sufficiently mitigated, the Commission should consider measures to make new wireless operations in the 3.5 GHz band more attractive to cable operator investment,” NCTA said (http://bit.ly/11XGl7z). “For example, the Commission should recalculate the size of the exclusion zones needed to protect government services from potential interference from cable Wi-Fi service."

The Satellite Industry Association raised similar concerns, and questioned whether a small-cell allocation is even necessary. “Before it undertakes fundamental changes that will affect existing licensees, however, the Commission must take a hard look at whether the evidence in fact supports a need for additional spectrum that can be met by allowing the introduction of small cells in the 3.5 GHz band,” SIA said (http://bit.ly/YoXtuC). “In SIA’s view, the projected shortfall in capacity and bandwidth may not be as significant as the Notice suggests, given the ability of wireless carriers to use a small cell infrastructure today to enhance use of existing spectrum allocations and offload traffic to more efficient wireline alternatives."

But Microsoft said the FCC should move forward. “Microsoft’s Spectrum Observatory, which collects frequency usage data from four sensor installations worldwide, has found that the 3.5 GHz band is largely unused,” the company said in its filing (http://bit.ly/VOAhfn). In Washington, D.C., for example, Microsoft found that during the busiest hour in the month of January the maximum occupancy in the 3.5 GHz band was never above 10 percent. “The average occupancy in the band was between roughly 0.05 percent and 0.1 percent,” its tests show, the company said. “So for the vast majority of January 2013, the 3.5 GHz band was about 99.9 percent vacant, and during the busiest hour it was 90 percent vacant."

AT&T said the 3.5 GHz band might be an example where sharing makes sense (http://bit.ly/VyKry2). “This spectrum has limited value for traditional CMRS and mobile broadband transmissions, but possesses propagation characteristics and other attributes that make it a potentially valuable test-bed for small cell deployments,” the carrier said. “Such small cell deployments could serve as a component of carriers’ heterogeneous access networks and also promote advances in machine-to-machine applications."

CTIA said in its comments (http://bit.ly/VyJuWg) the band “may offer a promising opportunity for innovative services that can support deployments of wireless broadband, including as a component of mobile broadband providers’ heterogeneous access networks.” CEA said spectrum sharing is still no substitute for spectrum clearing. “Dynamic shared access has the potential to be a useful tool to help address the spectrum shortage,” the group said (http://bit.ly/Yph5Pn). “This approach, however, represents a long-term vehicle to address the spectrum crunch. The technologies being explored have not yet been fully commercially deployed or proven.”