GPS vehicle locators

Yeah. LTE is very good out here, but the items are stored in a steel roof building, so not sure how well a gps will function.

So it can be network (terrestrial) based, space based (GPS) or a combination.

Yes, steel buildings will impede gps based systems but if it's in your building it doesn't matter

Battery life is the biggest challenge. Systems like the one Ray pointed out will serve well but have cost.

Then there are dog/ child trackers that are work arounds to fleet systems