Forgot to mention, if you are using a mobile router like the Netgear Nighthawk from AT&T that has external antenna connectors, you can hook them up to your rig's batwing antenna if it is prewired for the Furrion like mine. It is a really decent MIMO antenna. I ordered 2 12" antenna leads from Amazon that have a TS9 connector on one end and the SMA female on the other.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I used command strips to mount the router on wall near the prewire so I could utilize the built in 4g antenna on the rig. I also put in a 12v USB outlet to provide power to the router.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
The prewire for the Furrion router already has 12v power run to it, so this mounted on the wall next to it and gives me 2 USB power outlets. All total, the whole thing was less than $30.00.
If you have the Furrion Access pre-wire, this is definitely easiest and cheapest the way to go.