I'm currently at Freenet Funk. They use the O2 network. I still have a Huawei "Mobile Wi-Fi" device that starts with a SIM card, a mobile hotspot. The problem is, however, that the device is branded at 1&1. After I have plugged in the SIM card, it is indicated that it is in the network of 1&1 with 3G (LTE is not working). Do I pay extra now or how is that?
Go to Settings, there to network. Find out which knot you're connected to.