10+ GHz for 5G: FCC Expands Spectrum Frontiers for Fifth Generation Connectivity
U.S. aims to get ahead of the rest of the world in advanced wireless technology.
As we've reported, the FCC has been hard at work on the regulatory regime for future wireless "5G" technologies, which promise blindingly fast data speeds.
Would-be 5G wireless providers and device manufacturers particularly want wide swaths of millimeter wave (mmWave) spectrum - frequencies above 24 GHz - for fastest speeds and highest video resolution. An advantage to this spectrum: at present a lot of it is only lightly used. Because these frequencies work best at short range, many envision that the highest-speed service will add to, but not fully replace, current 4G technology. Best of all, transmitter and antenna technologies are close to being ready.
In the Report and Order (R&O) component of a massive, 278-page Report and Order and Further Notice of Proposed Rulemaking (Order), the FCC has made mmWave spectrum available for both licensed and unlicensed use. New rules provide for mobile use in the 28, 37, and 39 GHz bands. And the newly-opened 64-71 GHz band will provide a total of 14 GHz for unlicensed use of WiGig technology, similar to a higher-frequency version of Wi-Fi. Through the Further Notice of Rulemaking (FNPRM) portion of the Order, the FCC is looking to address a number of issues left open in the R&O portion. (The fact that some issues remained unresolved is not surprising, since the R&O was wrapped up in near-record time, for the FCC - just nine months after the rules were formally proposed.)
The FCC has followed through on its proposal to make available almost 4 GHz of spectrum for flexible licensed use in the 28 GHz, 37 GHz, and 39 GHz bands. Here "flexible" means that a licensee can use its frequencies for either fixed or mobile applications. This is a novel idea in the halls of the FCC - one that's been talked about for years, but is only now finally being implemented. The R&O creates a new "Upper Microwave Flexible Use Service" (UMFUS) in a new Part 30 of the FCC rulebook.
28 GHz Band (27.5-28.35 GHz)
This band is part of the old Local Multipoint Distribution Service (LMDS), auctioned in 1998 to great fanfare. LMDS was then touted as a potential major competitor to local telephone cable TV services, but it never caught on to the extent that the FCC (and the bidders) had hoped. Today fewer than half of the original licenses are still "active", according to the FCC. While probably far fewer are actually providing service, the incumbents will still retain some rights.
The band will be auctioned in county-sized licenses (although a majority of commenters favored larger areas). Of course, auction participants can bid on contiguous blocks of counties to make up whatever service areas they want. Existing LMDS fixed licenses will have to be subdivided into county-sized areas. LMDS licensees can add mobile services to their portfolios. Each county will have two 425 MHz licenses.
Previously authorized satellite gateway operations in the band can continue, either by protecting mobile operations or by acquiring their own UMFUS licenses.
39 GHz Band (38.6-40 GHz)
This is another unsuccessful fixed band, originally auctioned in 2000. Of 2,464 possible licenses (and 2,173 awarded at auction), only 870 currently exist - and again, probably fewer are providing service. As at 28 GHz, the incumbents will receive mobile authority.
Here the license areas will be "Partial Economic Areas" (PEAs), of which there are 416 in the United States and its territories. Each PEA includes specific counties, averaging about seven counties per PEA. PEA populations are highly non-uniform, varying from 56,000 (American Samoa) up to 25 million (New York City area). For a lot more than you wanted to know about PEAs, click here. Each PEA will have seven 200 MHz licenses. This differs from the current band plan, which has 28 50 MHz licenses per PEA, so some incumbents may have to repack their systems.
Satellite earth stations will be permitted, although each can claim only very limited protection from UMFUS operations.
37 GHz Band (37-38.6 GHz)
Unlike the bands above, this one is currently empty except for a small number of federal government users. Also unlike the other bands, the FCC will split this one into two different licensing schemes. The 37-37.6 GHz segment will be a single, nationwide shared block, to be used by both federal and non-federal users on a coordinated, co-equal basis. Details for sharing have not yet been finalized; they are a topic out for comment in the FNPRM, outlined below. The 37.6-38.6 GHz part will be subject to rules similar to those for the adjoining 39 GHz band, above, i.e., PEA-based licensing in five 200 MHz segments.
The band just below, at 36-37 GHz, is used by the Earth Exploration-satellite Service and Space Research Service, and part of it is used for radio astronomy. Functions include global weather forecasting and the study of ocean surface topography, ocean winds, and sea ice. The FCC declined requests to protect these operations with a guard band at 37 GHz, and also to limit operations near three radio astronomy observation sites.
64-71 GHz Band
The rules for the new 64-71 GHz unlicensed band track the Part 15 rules already in place for the 57-64 GHz unlicensed band just below. This provides a great opportunity for developers to take advantage of the widest swath of contiguous spectrum anywhere on the FCC rules. To make the band more amenable to WiGig technologies, the FCC did tweak the rules in various ways, including the elimination of a long-unpopular publicly-accessible coordination channel. The FCC rejected, at least for now, a proposal to allow operation onboard aircraft because of the desire to protect sensitive "passive" users, i.e., those who use the spectrum for scientific research.
FNPRM
The FNPRM portion of the FCC's Order is nearly as broad as the R&O component. It seeks comment on the potential use of additional bands for both flexible fixed and mobile uses: 24.25-24.45, 24.75-25.25, 31.8-33.4, 42-42.5, 47.2-50.2, 50.4-52.6, 71-76, and 81-86 GHz. Also up for discussion are frequencies above 95 GHz, which the FCC has not previously regulated. Included as well are requests for comment on particular issues that need to be cleaned up, including questions on the technical rules. As always, this calls for careful reading, but heads up to the following issues:
24, 32, 42, 47, 50 and 70/80 GHz bands: The FCC is trying to get ahead of the rest of the world with well-established policies for spectrum proposed for IMT (International Mobile Telecommunications-Advanced) use on an international basis, and to have something concrete for discussion and action at the 2019 World Radio Conference. Most of these bands would follow the licensing rules established for the new 27, 37 and 39 GHz bands, except for 71-76 and 81-86 GHz, which would follow the 3.5 GHz Citizens Broadband Radio Service.
28 GHz, 37 GHz, and 39 GHz bands: The FCC seeks comment on spectrum use requirements for these newly established bands, particularly as applied to combined fixed/mobile operations.
37-37.6 and 37.6-38.6 GHz: The FCC seeks more detailed information to help create better sharing arrangements between private users and the federal government.
42-43.5 GHz: The FCC denied a microwave industry group's request for fixed-service rules as to the 42-42.5 GHz segment because the FCC proposes flexible use there. It kept the request pending for the 42.5-43.5 GHz segment, which is used for radio astronomy, noting that fixed-only service can better protect the radio astronomy sites than mixed use can.
Above 95 GHz: The FCC asks a broad range of questions as to potential use and service rules for spectrum at 95 to 275 GHz, and possibly up to 1,000 GHz (well beyond the current capabilities of radio engineering).
Internet of Things (IoT): The FCC wants to know whether "performance requirements" - a term for network buildout and service rules - should be applied to various IoT applications.
Comments in response to the FNPRM are due by September 30, 2016; reply comments are due by October 31. You can submit your comments at this FCC website; enter Proceeding Numbers 14-177, 15-256, 10-112 and 97-95.
We can't recall when the FCC has tried to roll out drastically new services, using new technologies, in new frequency bands, under new rules - all in a very short time. Future consumers playing some descendant of Poki(C)mon Go on their 5G phones will never appreciate how much work it took to get there.