Big tech companies, plus Broadcom and the Public Interest Spectrum Coalition (PISC), separately told the FCC they fear nothing from indoor, low-power unlicensed use of 6 GHz spectrum and shouldn’t require frequency coordination. Replies were due Monday on an NPRM, in docket 18-295, with some other commenters urging caution (see 1903180047). “Comments make it clear that in the vast majority of locations, times, and configurations, [radio local access networks] would not be positioned to even potentially cause harmful interference to incumbents,” the tech companies said. Some commenters raise concerns, they said: “With few exceptions, these commenters either provide no empirical support for these claims or repeat flawed arguments that have already been presented and addressed in prior phases of this proceeding.” The filing was signed by Apple, Broadcom, Cisco, Facebook, Google, Hewlett Packard Enterprise, Intel, Marvell Technology, Microsoft, Qualcomm and Ruckus Networks. Broadcom separately said fixed-service proponents warn of a threat that doesn’t exist. “FS interests now focus on unlikely corner-case interference scenarios in arguing for additional regulation, Broadcom said: “In the vast majority of situations, however, RLANs will not be positioned to raise any harmful interference concerns at all. And an analysis of FS system operations shows that if the unrealistic combination of improbable events conjured by FS interests somehow were to occur, it would not degrade FS operations in the real world.” The record shows “diverse and strong support” for allowing unlicensed use across all 1,200 MHz from 5925 to 7125 MHz, and “broad support” for low-power and indoor-only use in the U-NII-6 and U-NII-8 segments without a coordination requirement, PISC said. “Base policies on risk-informed interference assessments and not unrealistic worst-case scenarios.” The Open Technology Institute at New America, Consumer Federation of America, Public Knowledge, Consortium for School Networking, Access Humboldt and X-Lab signed. They advised caution. NAB warned “no commenter has proposed an effective mechanism for protecting important broadcast auxiliary services operations” in the U-NII-6 and U-NII-8 bands. “Uncoordinated unlicensed use” here “risks crippling interference to licensed BAS services,” NAB said. Given the “already diverse and critical use of the spectrum, it is not surprising that … comments question the viability of adding millions or possibly billions of unlicensed devices into the band without causing interference to higher priority services that already rely on the spectrum,” said the National Public Safety Telecommunications Council.

Michael Calabrese, director of the Wireless Future Program at New America, urged relatively light-touch rules in the 6 GHz band, meeting Commissioner Jessica Rosenworcel on Feb. 19. Public interest groups hope the FCC will authorize use of the band indoors without automated frequency control across the U-NII-5 and U-NII-7 band segments, Calabrese said, he filed in docket 18-122, posted Friday. “Failure to set a power level at which Wi-Fi can operate indoors across the entire 6 GHz band, using off-the-shelf routers and low-cost devices, would sacrifice what is likely to be the greatest benefit of this rulemaking,” Calabrese said: “Without affordable, do-it-yourself access to the 850 megahertz in U-NII-5 and U-NII-7, a majority of homes and small businesses in particular will likely be limited to a single 160 megahertz channel between 6.875 and 7.125 GHz.” Replies were due Monday on a 6 GHz NPRM (see 1903180047).

Replies on the 6 GHz NPRM largely refuted claims in initial comments (see 1902190005), which included many from incumbents concerned about interference. The FCC appears committed to moving forward with unlicensed in 6 GHz, and licensed in the C band, and must decide on such issues as whether to allow use of the band indoors without automated frequency control (AFC) (see 1902250054). Replies were due Monday in docket 18-295.

The FCC approved 5-0 an order allocating the first bands above 95 GHz for Wi-Fi and other unlicensed use. Commissioners Geoffrey Starks and Jessica Rosenworcel voted for the order but raised questions, as expected (see 1903130057). The "spectrum horizons" order provides unlicensed use of 21.2 GHz of spectrum in four band segments and would permit experimental use on any frequency from 95 GHz to 3 THz.

Unlicensed use of the 6 GHz band may pose a threat to ultra-wideband devices Germany’s Marquardt manufactures, it said in early reply comments in FCC docket 18-295. Replies are due Monday. “It is very important for us and our customers that UWB with [its] demanding power limitations can continue to operate unhindered,” the company said. “Award only the least amount of spectrum required, and at as low a frequency as possible.” Earlier, the UWB Alliance said the FCC should authorize unlicensed use of only the 5.925-6.1 GHz part of the band, with out-of-band emissions below 61 dBm/MHz.

The FCC Office of Engineering and Technology rejected the Ultra Wide Band Alliance’s request for more time to file replies on the 6 GHz NPRM. Replies are due March 18 and the alliance asked for 14 more days. “Commission proceedings involving spectrum use can be expected to contain lengthy or detailed filings of a technical nature, and this proceeding is consistent with that model,” OET said Monday in 18-295. “We find nothing sufficiently unique or unusual that would warrant delaying the reply comment cycle.”

Initial filings on the 6 GHz NPRM confirm the FCC will face substantial pushback from incumbents. That's no surprise because of the amount of spectrum in play and many incumbents, industry officials said. The FCC appears committed to moving forward with unlicensed in 6 GHz, and licensed in the C band. One question is to what extent it will allow use of the band indoors without automated frequency control (AFC).

Consumer and rural broadband advocates are seeking “two significant improvements to ensure that Wi-Fi and other unlicensed technologies can keep pace with consumer demand and make wireless connectivity robust and affordable for every home, business, school and library” as the FCC addresses the 6 GHz band, Michael Calabrese, director of the Wireless Future Program at New America, told Julius Knapp, chief of the Office of Engineering and Technology. Public interest groups are urging the commission to “authorize low power, indoor-only unlicensed use across the U-NII-5 and U-NII-7 band segments without the cost and complexity of AFC [automated frequency control] coordination,” Calabrese said in a docket 18-122 filing posted Friday. “The failure to set a power level at which Wi-Fi can operate indoors across the entire 6 GHz band, using off-the-shelf routers and low-cost devices, would sacrifice what is likely to be the greatest benefit of this rulemaking.” Public interest groups also want the FCC to adopt rules for outdoor, AFC-controlled fixed wireless deployments “harmonized with Part 15 rules allowing higher gain antennas in the 5 GHz bands currently in use for rural broadband, enabling higher [effective isotropic radiated power] operations that cover larger areas more affordably,” he said.

The FCC identified the four band segments Friday to be allocated for unlicensed use in spectrum above 95 GHz in an order scheduled for a vote at the March 15 commissioners' meeting. The identity of the bands, which Chairman Ajit Pai discussed in a Thursday blog post (see 1902210048), had been the source of some confusion. The segments are 116-123, 174.8-182, 185-190 and 244-246 GHz, according to the draft order.

New York City warned in a Tuesday filing that opening the 6 GHz band to unlicensed use would cost the city money and any changes would take time to complete. “The City expends considerable financial and human resources to ensure that its public safety mission critical radio communications systems are reliable under all circumstances,” it said in docket 18-295, responding to the 6 GHz NPRM. The proposals “if enacted as written, will force the City to re-design many of its microwave backhaul links in order to ensure that the City’s mission critical land mobile radio systems continue to perform to public safety reliability standards under all conditions.” The city is concerned that in cases where fixed service (FS) microwave receivers are located in or on high buildings “within dense urban areas, a transmitting unlicensed device may interfere with the weak signal present at FS microwave receivers supporting public safety or critical infrastructure land mobile radio operations,” the filing said. The city is also concerned about restrictions on new or expanded FS microwave links for public safety and other operations, it said.