Group Communications and Charges; Technology and Business Models : 5th COST264 International Workshop on Networked Group Communications, NGC 2003, and 3rd International Workshop on Internet Charging and QoS Technologies, ICQT 2003, Munich, Germany, September 16-19, 2003 Proceedings - Burkhard Stiller, Georg Carle, Martin Karsten, Peter Reichl ((Lecture Notes in Computer Science))