Communication method for NLS drons

What communication is suitable for non line sight of drons which goes beyong the hills? As i found gsm bases system is not good for this since if the drone goes too much above the gsm towers their will be loss of communication. And the sattalite communicate service is expensive. I also had a plan to use radio transceivers as repeaters for non line sight of communication but installing this routers in places is also long process.
What kind of communication methd does commericial uavs use for this ?

We’ve used a nearby loitering UAV as a radio relay in the past.

Other than that, as you mentioned, 3G or satellite are your best options.