0. I really had to do this from the very beginning, so I asked my nephews how to start.
1. I had to find a provider and decided for A1 (at that time Telekom Austria).
2. It was easy from the home page to decide for the suitable service product
3. I made the order via the phone hotline given in the home page (late in the evening).
The call center agent checked immediately, that my phone connection meets the necessary preconditions.
4. I received a package via post service containing the necessary hardware equipment including the modem with WLAN function.
5. My new notebook was already equpped with LAN socket and WLAN features so it was no problem to set up the cable connections needed for the installation according to the printed documentation as well as the documentation on the installation CD.
6. The connection between computer and modem did work. The control light on the modem indicated a correct connection with the computer but faulty connection with the telecom server.
7. All the problem solving hints in the documentation did not apply.