Three TV Series, One Universe

I spent my entire childhood by watching the German police series "Alarm fur cobra 11", and once, in the episode "Highway Maniac" I heard firstly the song "keep hope alive", and when I googled the song, I stumbled to other, police (and not just) series "Third Watch", but i loved C11 as much, as I didn't wanted something similar, but one day, I founded and saw another German, action series "GSG 9", so I was looking for something another German action series, similar to C11, and when I founded the series, from c11 creators "Medicopter 117", I immediately started to watch this series and it impressed me as much, as it was harder to me, to rewatch C11 after this, and when I little tired from 117, I remembered about "Third Watch", and started to watch it too, and loved it very much too, and after that I decided to make a crossover between all this, three TV series, the events of my story will happen, as before, as while and as after the basic events of these three series.