How many geo-stationary orbital slots are left unoccupied that could allow pan European coverage?
All current satellite communication systems are based and planned on LEO/MEO constellations to maximise coverage above 60 degrees N/S, increase bandwidth, allow NRT data and voice transmission and also provide redundancy. Spacex, for example, has submitted requests for constellations adding up to around 40,000 satellites in total - and they are one of several such companies.