Dieter Hogrefe is full professor (C4) for Telematics at the University of Göttingen since 2002. He graduated at Philips Exeter Academy, USA, in 1976 and studied Computer Science and Mathematics at the University of Hannover, Germany, where he graduated with a diploma degree and PhD. His research activities are directed towards Computer Networks and Communication Software Engineering. He published numerous papers and two books on Internet technology, analysis, simulation and testing of formally specified communication systems. Prof. Hogrefe held full professor positions at the Universities of Dortmund, Bern, Lübeck, and Göttingen and visiting positions at UC Berkeley and Hamilton University. From 1983 to 1986 he was with the SIEMENS research centre in Munich and worked in the area of analysis of telecommunication systems. He was responsible for the protocol simulation and analysis of the CCS No. 7. Since 1996 Prof. Hogrefe is chairman of the Technical Committee Methods for Testing and Specification at the European Telecommunication Standards Institute, ETSI. He is married to Susan Hogrefe and has four children (Christian 1989, Luise 1990, Georg 1993 and Katharina 1998).