Communication Technologies for Vehicles 4th International Workshop, Nets4Cars/Nets4Trains 2012, Vilnius, Lithuania, April 25-27, 2012. Proceedings - Vinel, Alexey; Mehmood, Rashid; Berbineau, Marion; Garcia, Cristina Rico; Huang, Chung-Ming; Chilamkurti, Naveen (Springer Berlin Heidelberg, 2012)