COS 2 Experiment in Turin: Field Test on an Optical Cable in Ducts

"COS 2" is the second Italian field trial with an optical cable. In this experiment about 5 km of optical cable were installed in normal telephone ducts of the Turin local network between two telephone exchanges. The cable has a capacity of 8 fibers, but, for cost reasons, in 4 of the 5 km of cable only 3 fibers were inserted. An installation procedure was developed, allowing the independent laying of several cables in one duct; it was possible to pull up to 1 km of optical cable in order to minimize the number of splices. A special splice (Springroove®splice) and splicing technique, not requiring the use of a microscope or other intricate tools, were employed. Field measurements of transmission characteristics (attenuation and bandwidth) were performed by means of specially designed measurement equipment. An experimental 140 Mbit/s system was tested on a link about 9 km long (without intermediate repeaters) obtained using this cable.