I'm kinda new to mobile comunications, I know 3g bands are different in each side of the Atlantic Ocean but what about 4G? I have been researching but I didn't really understand if the same device working in (lets say) Spain will work in USA. Some of the modems I have been looking at have a nice bunch of working bands but I don't know the differences between them or how common they are over the world.
I was thinking about a sim7020, do you guys think this will serve my purpose? I also need it as cheap as possible because we need a bunch.
Thanks in advance
Edit (forgot to say): I'll be using "worldwide" m2m iot sims, they should work I guess?