@ruff nearly every time posts with interesting background informationg …
The average linux admin would solve the problem by just having an wake-up interval - which clearly doesn’t help in the phone-over-ip setup if you’d expect a signal when an sms-over-ip or a call-over-ip arrives.
Another approach would be the one I see for the pinephone: They start to replace (parts of) the system running on the modem and I’m wondering whether it would be possible to implement very simple services there.
E.g. the modem could listen for traffic and when some data (like voice and sms also do) matches a certain pattern it could wake up the mainboard. Very rough and there is no real concept behind it, but it would implement some kind of wake-on-lan for mobile connection.
Well, we’ll see whether you’re right or not … The pinephone does suspend already and we can follow the progress to make it last longer unsuspended.