As I understand it, and Andrew will correct me if I'm wrong, you (probably) do not need a router.
You may be confused by the fact nearly everyone talks about routers for ADSLx, where they mean ADSLx routers, which are all-in-one boxes containing a modem, a router and a four-port switch.
It's the modem part that connects to the internet, and if you only have one computer needing access then the rest can be unnecessary.
In particular, 3G dongles are modems

.
4G is (I think) available in the States, but will be a while before it gets here. I believe it is waiting for the analogue TV frequencies to become available to run it on.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - IDNet Home Starter Fibre.
Live BQM.
"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.