Mobile network on Android based media player box - is it possible?

A

AC Question

Hi.
Hope the title is clear. Let me expand: we're using Android media player boxes (aka smart tv boxes) for signage display in various locations (with viewneo player, if that rings any bells). The playlist is created and deployed via a web interface, then the player updates accordingly via WiFi or Ethernet.
Now, the problem is, wifi or ethernet is not available at all locations, and I was thinking if we could use USB 3G modems? What I could find out so far, is that Android needs to be rooted, then the modem can be enabled (for tablets and phones etc) but these players don't even have a "mobile networks" option in the settings, so I don't even know if it's possible at all.
Any input is very welcome. I'm good with computers and stuff, but I'm new to Android stuff beyond just using my phone :)
Thank you.