FCC proposes rules for 4 different spectrum bands above 24 GHz for 5G networks

WASHINGTON -- The FCC proposed new flexible rules for four different bands of high-band spectrum above 24 GHz designed to lay the foundation for 5G networks in the U.S. market. FCC Chairman Tom Wheeler said at the agency's monthly meeting that with the adoption of the proposed rules, the FCC is "taking a serious leap that creates a competitive opportunity for this nation to be a leader in the forthcoming 5G world."

The specific bands that will be studied for 5G services include the 27.5 to 28.35 GHz, also known as the 28 GHz band; the 37 to 38.6 GHz band, also known as the 37 GHz band; from 38.6 to 40 GHz, known as the 39 GHz band; and the 64-71 GHz band.

Commissioner Jessica Rosenworcel noted that these are the bands the FCC will propose to be considered part of 5G standards next month at the World Radio Conference 2015 in Geneva.

The FCC will propose in its Notice of Proposed Rulemaking a variety of rules for the bands, including geographic area licensing, unlicensed use and a licensing mechanism that can accommodate private enterprise uses and traditional mobile broadband deployments. The rules aim to promote coexistence among those alternatives, especially because several bands are shared with satellite services and with federal government and fixed users.

The 28 and 39 GHz bands are being contemplated for small cell deployments, with the proposal saying that the spectrum will be licensed as county-sized geographic services areas which auction winners could aggregate into larger service areas. Existing licensees could continue to do fixed, mobile or a combination of those services in those bands.

For the 37 GHz band, the FCC contemplates a hybrid licensing scheme that would grant operating right by rule to building and property owners while also establishing geographic license areas for outdoor services on a county-sized license area. Enterprise and industrial users could use the spectrum for indoor operations.

And finally, for the 64-71 GHz band, the FCC is proposing unlicensed use and more spectrum for services like WiGig while also protecting incumbent federal users. The FCC is seeking comment on how to ensure compatibility and facilitate coexistence.

"It was once thought that frequencies above 28 GHz could not support mobile services because their wavelengths were too short and the signal propagation losses were too high," Commissioner Mignon Clyburn said. "But industry engineers have now turned these weaknesses into strengths by finding ways to use short wavelengths to build dynamic beam-forming antennas to support high capacity networks that are small enough to fit into handsets. Many expect that these engineering advances will lead to 5G networks that will offer much higher data speeds and substantially lower latency than what commercial mobile services offer today."

Rosenworcel acknowledged the weak propagation characteristics of higher-band spectrum but said that dense networks of small cells could help overcome that and also called for new FCC rules to speed up the deployment of small cells. She noted that the WRC conference presents an opportunity to harmonize different 5G bands and thus create economies of scale that will lower the cost of 5G network gear and devices.

Both Commissioners Ajit Pai and Michael O'Rielly said they wished the FCC had included more bands in the item, as they had proposed. Pai said he suggested "including 12,500 MHz of spectrum in the 24 GHz band, 32 GHz band, 42 GHz band and the 70 and 80 GHz bands. Unfortunately, the votes were not there, and the Notice does not propose moving forward on them. The Commission's decision to sit on literally thousands of megahertz of spectrum that could very well be used for licensed and unlicensed innovation is a lost opportunity. The Notice offers no persuasive reason for leaving these bands on the cutting room floor." Pai also said "we don't know which millimeter wave bands will prove to be viable homes for 5G or other wireless uses." 

However, Wheeler said that the proposed rule will include 3,850 MHz of spectrum, or six times the amount of all the commercial spectrum the FCC has ever authorized for wireless use. While not all spectrum is created equal due to the laws of physics, Wheeler said, it still represents a "huge increase."

To give the U.S. a lead in LTE deployments, Wheeler said, "spectrum was made available quickly and in sufficient amounts, and secondly, great flexibility was given to those to use the spectrum in expansive ways, unlike the kinds of government dictates that existed in other countries. We need to follow that kind of game plan in the 5G world."

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