I use an old Wilson Electronics 3G booster that supports HSPA+ with a trucker antenna and have gotten some amazing boosts. Had one case where we were camping at a remote lake and got no signal at the campsite but occasionally got 1 bar at the lakeshore 300 feet away. The boost brought the signal in so it was useable.
Another case we were in a caldera where we have never got reception before but happen to be in a site that had a view of a low spot in the caldera rim. I was able to at least do text messages but donโt remember if I could do a phone call. Couldnโt do web page stuff though.
I attach the trucker antenna to a slide awning arm so the top up the antenna ends up about 13โ in the air.
2006 Jayco 28', E450 6.8L V10, Bilstein HDs,
Roadmaster Anti-Sway Bars, Blue Ox TigerTrak