DIVAC - an experimental optical-fibre communications network

Nowadays 'optical communication' usually means the exchange of information with the aid of optical fibres. The term is also applicable, however, to visual communication by semaphore or similar methods. In France between 1793 and 1852, for example, a visual communication network designed by Claude Chappe was in use. This worked with a system of moving arms that could be viewed by telescope from distances of up to 20 km. The network eventually had 556 stations and covered a totallength of 4000 km [*1. Although this network was very successful, it probably delayed the introduetion of the electric telegraph in France by 20 years or more. Today something similar is happening. The introduetion of optical-fibre networks is being delayed by the presence of conventional networks that work well, although optical fibres undoubtedly have distinct advantages over conventional copper cables for many communication applications. Toprovide a general insight into the many possibilities offered by optical-fibre networks the DIVA C project was set up (DIVA C is an acronym for the Dutch words standing for digital connection between subscriber and exchange via optical fibres). In the DIVAC project experience is being gained not only with new technologies but also with new services. Theparties cooperating in the project are the Dr Neher Laboratory of the Netherlands Posts and Telegraph Service, the Delft and Eindhoven Universities of Technology, Philips' Telecommunicatie Industrie B. V. and Philips Research Laboratories.