Master of Science, Technology University, Bandung, Indonesia, 1955. Doctor of Philosophy., Technology University, Munich, Federal Republic Germany, 1967. Engineer Philips, Eindhoven, Holland, 1955-1956.
Systems engineer Siemens Ag, Munich, 1956-1958. Director Panatraco Ltd., Jakarta, Indonesia, 1958-1970. President Pansystems, Jakarta, since 1970.
Consultant Telecommunications Administration, Jakarta, since 1975, International Telecommunication Union, Geneva, 1980-1985.