Every curriculum in traffic- or queueing theory presents Engset.s formula. Published in 1918 this relatively simple, yet powerful piece of scientific achievement became one of the methodological pillars for the designers of communication networks. His basic model is developed from scratch in an unpublished report in 1915. This book tells the story of a remarkable man - Tore Olaus Engset (1865-1943). Fully occupied with managerial duties of the Norwegian Telecommunication Authority, his spare time he devoted to developing methods for handling teletraffic. Also, he acted in the theoretical breakthroughs of physics during the first quarter of the twentieth century. A cooperation between Professor A. Myskja and the editor of Telektronikk, O. Espvik, has resulted in a thorough biography of T.O. Engset. His most important traffic-theoretical works are translated into English and discussed from the viewpoint of current knowledge. About the editors Arne Myskja is Professor Emeritus at the Norwegian University of Science and Technology, where he has been employed since 1960. He was formerly with the Norwegian Telecommunications Administration, and has had teaching/research assignments in the US, Denmark, Sweden, Australia and France. His main areas have been switching systems and teletraffic theory. Most recently he has devoted his time to studies related to T. Engset. E-mail: arne.myskja@item.ntnu.no Ola Espvik is Senior Research Scientist and Editor of Telektronikk, the Norwegian professional journal of telecommunication. He has been with Telenor R&D since 1970 doing research and project leadership in numerouse projects in traffic engineering, simulation, reliability and measurements. His present research focus is on Quality of Service and Quality Assurance in which he has been active in both ITU, IEC National Committee, and EURESCOM. E-mail: ola.espvik@telenor.com.
