The baseband radio still communicates with the tower in airplane mode.
That's interesting. Does anyone have a further source or description of that behaviour?
It's required for emergency calls to quickly enable routing of said emergency call. They work even with no SIM or IMEI in the phone in some countries, though most western countries are starting to require SIM cards due to abuse (SWATting).
Any Links / docs discussing that? I didn’t find anything about this in a bit of searching.