Now I was successful and got the update A.0111.
First I switched off the FP3 and removed my Vodafone Germany SIM card from slot 1.
Then I inserted a Telekom D1 SIM card (a prepaid data card which is normally used in my notebook) in slot 2.
I turned the FP3 back on and the update was available immediately. Then the update was installed. The last step was to turn off the FP3 again, remove the Telekom D1 SIM card and reinsert the Vodafone SIM card.