Radu Popescu-Zeletin is Professor at the Technical University Berlin, and, since its foundation, has been director of the Fraunhofer Institute for Open Communication Systems, FOKUS, (formerly a GMD Institute). For many years he was head of the Research and Development Department of the BERKOM project at Deutsche Telekom. He has published numerous articles on distributed computer systems and applications. He is an active member of numerous standardization committees and is a leading player in the development of telecommunication standards. As holder of the Chair of Open Communication Systems...