And while I read models of routers I can't seem to find what this mobile broadband is coming in on.
If it's some device with Ethernet, those router will do. If it's WiFi then you need a WiFi client device to feed some Wireless Access Point (WAP) or a router setup as a WAP. This is mildly advanced which I will only guide. I can not supply a step by step as each device varies.
I've recently changed over from wired ADSL to mobile broadband. After seeing favourable cnet review, I've acquired an ASUS AC2400_ RT_AC87U router. Now I'm looking for a robust wireless modem, preferably with own aerial, to feed the WAN signal from my ISP to the ASUS router via its ethernet WAN port. I tried the TP-Link M7350 but it didn't even get to first base with basic modem functions. Any suggestions for a wireless modem that will definitely provide this connectivity, please?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic