There are standards for each part of that process, both reading the ADC and transmitting data over a low-power WAN. The problem is that on its own, that isn't

There are standards for each part of that process, both reading the ADC and transmitting data over a low-power WAN. The problem is that on its own, that isn't a saleable product, everyone who has a need for that would be able to make it cheaper if integrated into their product as-a-whole. Integration is everything.