What you could do, however, is get an USB-stick 4G modem (usually called a "mokkula" in finnish BTW) and stick that into da USB port of your device. With right kind of SW tweaks you should be able to run your data connection through that external modem and still have the internal modem take care of your voice traffic.
You can even run the modems with active 3G and 4G data connections in parallel, achieving better throughput than any of your friends with their fancy modern Android/iOS devices