AT&T and Verizon have informed the FCC that they will lower the power levels of their 5G services using C-band spectrum for six months, but it’s pretty clear they’re not thrilled about it.

In a missive to FCC chairwoman Jessica Rosenworcel, the US operators confirmed they will minimise energy coming from C-band sites nationwide and to a greater degree from sites near public airports and heliports with a view to allaying concerns about interference with the performance of radio altimeters used in aviation that share the same frequencies.

This latest move comes after the pair recently agreed to delay the launch of their first 5G services using the C-band frequencies by one month from their initial timetabled date of 5 December to allow more time for discussions with the Federal Aviation Administration (FAA) regarding their ability to safely co-exist in the spectrum. As such, this six-month power reduction commitment runs until 6 July… unless the aviation industry can prove that there really is a problem. Or as the telcos themselves put it in a footnote to their FCC letter, “unless credible evidence exists that real-world interference would occur if the mitigations were relaxed.”

AT&T and Verizon are voluntarily making this move to enable further analysis by the FAA, although they are perhaps concerned that not to do so could mean enforced delays to their service launches.

Either way, it’s obvious from the tone of their communication with the regulator that they are not happy about the situation.

“Wireless carriers, including AT&T and Verizon, paid over $80 billion for C-band spectrum—and have committed to pay another $15 billion to satellite users for early access to those licenses—and made those investments in reliance on a set of technical ground rules that were expressly found by the FCC to protect other spectrum users.” That’s the second sentence of their letter. And it’s essentially a polite way of saying “hey, we shelled out an absolute fortune for this spectrum and you told us everything would be fine.”

The telcos go on to detail the benefits 5G will bring to the US as a whole – to consumers, the economy, and to the country’s position on the global stage – as well reminding the regulator that their 5G networks will fully comply with its own C-band rules, “which are carefully crafted to allow C-band 5G use to safely co-exist with aviation.”

That last point, once you look past all the nationalistic fluff and barely-disguised displeasure, is the crux of the matter here. AT&T and Verizon fully believe that their C-band networks pose no danger whatsoever to the aviation industry. And they have data to prove it…or at least to back up their point.

The telcos note that 5G has been rolled out in the C-band in nearly 40 countries, using hundreds of thousands of base stations, “without any reported incidents of harmful interference to radio altimeters and without the FAA expressing any concern regarding the safety of US-registered aircraft operating in those locations.”

They give Japan as an example, where tens of thousands of C-band base stations have been deployed with only 100 MHz of separation from altimeter operations; by contrast the US provides for a minimum of 220 MHz separation, and the initially 5G launches will have 400 MHz separation. Meanwhile, a number of European countries have operated 5G in frequencies including the 3.7 GHz-3.8 GHz segment for a number of years with permitted power limits higher than those laid out for urban areas of the US, they argue.

Their letter also includes a litany of different examples of cellular services coexisting with aviation without adverse effects.

Further, “the RTCA Report—which is the primary basis for the FAA’s and RA Stakeholders’ erroneous claims of harmful interference—has been thoroughly debunked and consistently dismissed by regulators around the globe,” they said, referring to a widely circulated interference report produced by the aviation industry body of that name.

Oh, and the coup de grâce: “We cannot afford to let China and other competitors gain an advantage due to a self-inflicted and unnecessary delay, especially for purported risks that have not been demonstrated in any other C-band deployment already operating in nearly 40 other countries around the world.”

That’s right, they played the China card. Given the fragile relationship – and that’s putting it mildly – between the US and China, they probably could have just gone straight for the “don’t let Beijing win” angle and saved themselves a few thousand words.

As it is, the operators have set out their argument in detail and have made it clear that come July the power is going back up and there will be no further delays in C-band 5G rollout. Which is hardly surprising, given the size of the investment they need to make a return on.That was special

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