Thanks for all your replies. I've just returned from my flight trip to Germany. My ultralight is TL-2000 Sting with VHF radio and mode C transponder.
I have two more questions:
1. Can you give me some explanations of what RAI is and examples of what information it broadcasts?
2. How can I find a military airspace is activated or not on the day before actual flight? I know NOTAMs. Is there any other source of activation notices like AUP (Airspace Use Plan) etc?
Many thanks!