One interesting technology in IoT field is Sigfox.
If you want to connect stations equipped with Sensors, in the field, with a Cloud infrastructure, you need wireless connectivity.
LTE and 4G are not an option now. Too expensive, in terms of money and power.
If you need only to send few bytes per seconds, Sigfox technology is a really inexpensive technology and Arduino has built a great board for Makers: MKRFOX 1200.
I have tested it. This is a first article on the subject, in Medium: "IoT, Arduino and Sigfox"
