I'm looking to build an Openwrt router that can connect via 4G to our local provider. The provider is known as Altice mobile and requires the use of a SIM card. Altice is actually a combination of AT&T and Sprint towers here in the USA. What are my best options for getting a cellular router going here at my cabin?
Is there an off the shelf router that I should be looking at that includes all the necessary hardware?
Is there a USB dongle that OpenWRT supports that I can plug into my existing router?