Since nobody interested in digging out that rabbit hole, I just lurked a little, and that's what I found:
https://whois.ipip.net/AS14593
Starlink have autonomous system with ID AS14593. This AS have only 206,080 IPv4 adresses that is too low for woldwide provider.
On "Graph v4" tab you could research direct connections AS14593 have with other AS'es. On "Upstreams" tab you could find upstreams of Starlink, i.e. channels Statlink use to connect to internet.
Mostly it connected to usual backbone providers and IXes, but there is some random networks I found interesting on the quick view.
- AS46997 NATOLAB - Black Mesa Corporation, US
- AS11164 INTERNET2-I2PX - Internet2, US
- AS14630 INVESCO - Invesco Group Services, Inc., US
- AS1798 OREGON - State of Oregon, US
- AS2152 CSUNET-NW - California State University, Office of the Chancellor, US
- AS207841 INFERNO - Inferno Communications Ltd, GB (some here will be enjoyed by that name)
- AS34019 HIVANE, FR (suspicious because it is a very small murky non-profit network with direct connection to Starlink AS)
- AS293 ESNET, US
You could continue that digging if interested. There are other tabs you could explore. There are tons of info you could find interesting.
SpaceX also have AS27277 autonomous system - http://whois.ipip.net/AS27277
I don't know answer too. May be some clue could be found in one of that upstreams in the list?
Then it looks overengineered. You could transmit that tiny bits of control info even inside GPS signal or through something like ORBCOMM. Applying permissions is one-way thing, and there is always will be some ground cellular network nearby and within at most few hours of time, if phone commanded to send some data to BigBrother.
Hardly there is exist a task where they need two-way realtime communication in the regions without cellular network. Not many people live in such places today and hardly they use latest phones.