Verizon, AT&T, and T-Mobile spent nearly $100B for their C-Band spectrum (including relocation costs). I think that creates a lot of pressure for them to be allowed to put them to use. I'm not saying it should, just that it does.

I think the US wants to be a 5G leader and it sees delays as potentially sacrificing that leadership. This might not be a real concern, but people complain anytime the US isn't the #1 in something and blame everything from politicians to capitalism. At the same time, it seems reasonable to believe that companies that have access to new 5G capabilities (speed, capacity, latency) will be able to develop and gain marketshare in new services. If American companies are going to develop the next generation of NewThings, playing around with the capabilities and limits of 5G networks in the real world will be an important part of that.

We've seen different countries with different scenarios. European countries that have nearly twice the guard band; countries that are mandating down-tilts; countries that have strict power limits; countries that don't have as strict power limits and are comfortable with the risk.

Personally, I don't understand why we didn't go with a phased approach. Set low power levels and a downward-tilt mandate. Ease the restrictions month by month and measure the real-world interference. Sure, maybe it means that C-Band networks aren't quite as good as they could be for 6 months, but I think predictable goals and timelines based on real-world data would satisfy cell carriers (who at least state they're confident that there will be no issue).

> 5G user equipment (mobile phones) that may be operating onboard aircraft were also found to exceed the safe interference limits for Usage Categories 2 and 3.

In some ways, this is what I'm more worried about. People have a smug sense that their phone can't interfere with planes and that regulations around cell phone use on planes are just BS. While the FAA/FCC will be able to enforce restrictions on cell carriers, it's going to be impossible to enforce it on users in-flight. You can't effectively make sure that devices are in airplane mode. Flight attendants can't see the indicator on my device (or lack thereof) when quickly walking up and down the aisles.

If C-Band causes interference with radio altimeters, I can see the FAA and FCC adding exclusion areas around airports, mandating antenna down-tilts and lower power levels in certain areas, and other mitigations. I think it's reasonably easy to get AT&T and Verizon to implement those and reasonably easy to check compliance. They might fight it, but it's still reasonably easy.

I think if C-Band phones cause interference, it's going to be a problem since we simply won't be able to police everyone on planes.