The city of Vienna offers a broad range of affordable hotels. Anyway, the following list provides a brief overview of hotels which are suggested by the conference organizers:

2* HotelFranzenshof15 (direct line)
3* HotelAustria Classic15 (direct line)
3* HotelCapri15 (direct line)
3* HotelIbis Wien Messe15 (direct line)
3* HotelKunsthof20 (direct line)
3* HotelPost18 (direct line)
4* HotelAustria Trend Hotel Lassalle15 (direct line)
4* HotelPark Inn by Radisson10 (walking)
4* HotelNH Danube City10 (walking)
4* HotelWandl20 (direct line)

* Distance to congress venue in minutes by public transportation

There are much more available rooms in Vienna which are very good connected with the conference location by public transport. Additional rooms can be found at http://www.wien.info/en/hotels.