Design of high speed fiber optics backbones for pulp and paper mills

In late 1995, the data communications networks at the Fletcher Challenge Canada´s Crofton pulp and paper mill had reached capacity and was suffering from overload conditions. The large growth in process control information and personal computers over the past few years was straining the existing coax and fiber optic systems´ ability to reliably transfer data. In addition, the increased network complexity made the troubleshooting of the networks extremely difficult and time-consuming. This paper discusses the design methods used to create a new fiber optic backbone that would provide the data carrying capacity and reliability needed for the pulp and paper mill´s computers and control systems. High speed network technologies such as ATM (asynchronous transfer mode), FDDI (fiber distributed data interface) and fast Ethernet were compared for their suitability in industrial environments. The design also incorporated Ethernet switches so that the existing Ethernet networks could attach at minimal cost. These switches subdivided the single large network that originally existed into approximately 24 subnetworks. This division greatly increased the network´s allowable traffic capacity and prevented problems in any one area from propagating throughout the mill, thus reducing network and process downtime.