Photo by freddie marriage on Unsplash

Not long from now, your new phone will come with 5G mobile data service: dizzyingly fast with near-zero latency (delay). But don’t expect service everywhere. 5G needs high frequencies for its high data capacity; but the physics of those frequencies means the range will be short, a few hundred meters at most. This will require miniature cell towers in each city block, mounted on light poles or the sides of buildings – that’s fine for downtown, but maybe not out in the suburbs. Indoor service will need an indoor base station, so 5G will work in well-appointed office buildings, but probably not your neighborhood restaurant. Where it does work, though, those silly cat videos will download in a flash.

The FCC calls 5G Upper Microwave Flexible Use Service, or UMFUS. The agency is doing the hard and thankless work of identifying radio spectrum for UMFUS, figuring out how UMFUS can share with other users of the bands, and working out operating rules to promote widespread coverage with a minimum of interference.

The FCC took a big step forward with its catchily-titled “Third Report and Order, Memorandum Opinion and Order, and Third Further Notice of Proposed Rulemaking.” This is a long, dense document in itself, and the fifth major release in a complex proceeding. All we can provide here is a superficial summary.

There are five UMFUS frequency bands – 24, 28, 37, 39, and 48 GHz – and two more proposed at 42 and 51 GHz. Three of the bands – 24, 28 and 39 GHz – are repurposed. The FCC auctioned off licenses for fixed microwave use of these same bands in the 1990s and 2000s, but later took back thousands of licenses because the auction winners had not met their obligations to construct facilities. The fixed licenses still in force in the 28 and 39 GHz bands have been converted to UMFUS licenses. Plans are underway to re-auction the 24 and 28 GHz bands.

The FCC activity at this stage is mostly tying off loose ends: adopting rules proposed earlier, denying reconsideration of rules adopted earlier, and proposing new rules to close out controversies. Even by CommLawBlog standards, this stuff is deep in the weeds. It won’t interest everyone. So we’ve kept it simple and listed the more important elements below for readers who are following the proceeding. Still, if any of this affects you or your business, we urge you to make a pot of strong coffee, click on the link above, and sit down for a long night of reading.

Here is what the FCC decided.

Performance metric: On the contentious question of what a licensee must build out to qualify for renewal expectancy (the issue that cost the prior licensees their licenses), the FCC added a new metric: demonstrating coverage of at least 25 percent of the licensee’s geographic area, or equipment operating in at least 25 percent of census tracts. This alternative is in addition to the existing criteria.

Mobile spectrum holdings, another controversial topic, refers to limits on the amount of spectrum that any one carrier can hold. The FCC had originally put a pre-auction limit on the 28, 37, and 39 GHz bands, fearing that the largest and best-funded carriers might use their superior funding to outbid everyone else, control large amounts of the spectrum, and thereby reduce competition. But the FCC has now changed its mind and removed the limits from all UMFUS bands at the request of … any guesses? … yes – Verizon and AT&T. Instead, it will apply a post-auction, case-by-case review of each carrier’s holdings.

24 GHz satellite sharing: The FCC is allowing fixed satellite earth stations in the 24.75-25.25 GHz sub-band, subject to limits on numbers and locations to minimize interference to UMFUS users. They can be used for either feeder links or service links.

24 GHz interoperability: Mobile or transportable equipment capable of operating anywhere in 24-24.45 or 24.75-25.25 GHz must be able to operate on all frequencies in those ranges.

26 GHz: The FCC proposes adding this band to the UMFUS mix, if there is a practical way to protect federal incumbents. The FCC also asks whether Elefante Group’s proposed use of the band for communication with high-altitude platform stations would be compatible with UMFUS.

Lower 37 GHz: The FCC wants to promote a variety of innovative applications here, and will license the band in six channels of 100 MHz each. It asks for help in specifying license areas and in finding ways to coordinate with federal government users.

42 GHz: The FCC proposes licensing this band for UMFUS. All agree that radio astronomy operations in the band need protection, and the FCC lists some possible measures, but has not yet said which ones it plans to adopt.

51 GHz: The band is under consideration for UMFUS, but also allocated to satellite use. The FCC proposes limits on earth stations similar to those in the 24 GHz band, above.

The good news: when you have your new phone and are enjoying super-fast 5G service, you won’t have to think about any of this.

(FHH represents clients in this proceeding.)