The problem with interference with radar altimeters was known a long time ago. Someone (FCC? FAA?) decided to go ahead with 5G anyway because the RF spec for RA's was ignored by the makers of RA's. If all the RA's obeyed the spec there would be no problem because there would be no signal overlap. But it was cheaper to ignore the spec and had no consequences for a long time. Now there are consequences and the two giants will have to fight it out. My guess is the cellular companies are going to end up paying to replace all the altimeters, but who knows, maybe the cellar companies will force the aircraft owners to pay for the upgrade. The aircraft owners would then sue the RA makers who would then go bankrupt and then we'll have no RA makers. Either way it is going to disrupt both air traffic and 5G deployment for quite a while. Quite a mess they've created.