As expected, the FCC issued updated proposals regarding a three-tiered access and spectrum-sharing model for the 3.5 GHz band, with a flexible approach now being proposed for the priority access tier that could include auctioned licenses under certain conditions.
The Citizens Broadband Radio Service, first proposed in December 2012, would rely upon spectrum-sharing techniques to open up a total of 150 megahertz in the 3.5 GHz band for general consumer use, carrier-grade small cell deployments, backhaul, fixed wireless broadband services and more.
A Further Notice of Proposed Rulemaking (FNPRM) issued by the FCC at an open meeting this week targets the 3550 MHz and 3650 MHz band and also seeks comment on extending the proposed service to the 3650-3700 MHz band, which is currently used by wireless Internet service providers (WISPs) to provide broadband in rural and underserved areas.
Interoperability would be required across all three tiers throughout the 150 MHz, which would help drive economies of scale for compatible equipment.
The proposed access and sharing model comprises federal and non-federal incumbents, priority access licensees (PALs) and general authorized access users. Supporters of spectrum sharing between federal users and others in the 3.5 GHz band say it is perfectly suited for flexible licensing because federal use in this band occurs primarily around the coasts, meaning the band is less encumbered elsewhere. However, due to the high population densities along the coasts, some 60 percent of the U.S. population would be in an exclusion zone.
Under the FCC's updated plan, targeted priority access licenses would be made available for multiple uses, including mobile broadband. In addition, general authorized access use would be allowed in a reserved amount of spectrum and on an "opportunistic basis" for consumer- or business-oriented purposes, such as home wireless networking.
The FCC's approach to the priority access tier now includes PALs that could end up being auctioned. The licenses would not be restricted to certain entities but would be open to all. A 10 MHz PAL, for one census tract, would be good for one year but could be aggregated for up to five years.
"If more than one entity wants the same license for the same year, there will be an auction," Commissioner Mignon Clyburn said.
Clyburn said the goal is to establish a license with lower administrative costs that would allow for micro-targeted network deployments as well as easy aggregation "to serve a larger footprint for a longer period of time." She noted those features should attract larger carriers and encourage them to invest in equipment for the band.
Commissioner Michael O'Reilly voted for the FNPRM, but cited problems with the PALs' design. He noted that a licensee building a network during the short-term PALs licensing period would not be assured of maintaining its priority access after that time.
Also, licensing by census tracts means there would be some 74,000 licenses. "As a result, applicants could face the difficulty of bidding on thousands of licenses in order to cover any one metropolitan area," O'Reilly said.
The commissioner noted he still prefers clearing federal government users and reallocating over sharing. "The 3.5 GHz band will be one big experiment in terms of the proposed sharing design and licensing scheme," which could be altered in the future if problems crop up, he said.
Because the 3.5 GHz spectrum would be shared, a dynamic database or multiple databases must be created to manage access and operations across the three tiers. This is how shared access is managed in the TV white space (TVWS) spectrum that sits between vacant TV broadcast channels.
Advocates of spectrum liberalization supported the FCC's FNPRM, which also seeks comment on technical, auction, and allocation rules for the 3.5 GHz band.
"Opening the 3.5 GHz band would not only promote shared small cell use and rural broadband deployment, but it will benefit countless stakeholders including public safety, small businesses, educators, and consumers through improved wireless broadband access," said the Wireless Innovation Alliance, which is made up of members including Google (NASDAQ: GOOG), Microsoft (NASDAQ: MSFT), Spectrum Bridge and Dell.
"We need to reorient the nation's spectrum policy toward more flexible and efficient approaches to harness the full potential of our spectrum resources," added WiFiForward, which is made up of members including the Arris Group, Best Buy, Comcast, the Consumer Electronics Association, Google, Microsoft, Time Warner Cable (NYSE: TWC) and others.
CTIA Vice President of Regulatory Affairs Scott Bergmann said that while 3.5 GHz band "holds promise for a variety of services, including small cell deployment and wireless backhaul," the association believes "it is critical for the FCC to establish the right incentives and certainty to promote investment and innovation in this band."
A version of the three-tiered sharing framework for the 3.5 GHz band was first proposed by the President's Council of Advisors on Science and Technology (PCAST) in a July 2012 white paper.
- see this FCC release
- see this Wireless Innovation Alliance release
- see this WiFiForward release
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