The phone will communicate with your network over wifi, and replaces both the Raspberry PI and the HAT.
The phone will communicate with your network over wifi, and replaces both the Raspberry PI and the HAT.
Carriers may be keeping a small (relative) amount of capacity up and running, but in the meantime prevent new activations (ATT does this with there 3G network for example), so "coverage" is a bit misleading in many cases.
Oh wow. Various types of monitoring use cellular, house alarms etc.
Are those things just using LTE now?
For outgoing SMS, have Tasker or Macrodroid watch an email inbox and send emails to that inbox with a format like email subject line = recipient phone number, email message body = SMS body. Then parse it through those automation apps and have it send the SMS for you.
I did something like this before and it worked decently well but I haven't had the best luck with getting Android apps to run stable for long periods of time without manual intervention. Not sure if it was battery optimization settings or what.