Algorithm for Determining the Optic Fiber Blowing Distance in Telecommunications Underground Networks

The paper presents some conclusions on the differences between the manufacturers' indications and the in situ practical observations of the optical fibers communications networks. Following the experimental results on preinstalled optical fiber telecommunication underground networks, blown by specific equipment, it is proposed a mathematical model for the whole system “network-equipment”, which can explain the physical phenomena. The experiments were developed made for real tubes, penetrated by optical tubes, both in laboratory and on real networks, and the results were similar. The differences from these real tubes and the tubes proposed for the ideal case is that these tubes are penetrated by several microtubes and that they are placed in positions similar to the real ones founded in practice. The providers technical specifications do not presents the differences between the laboratory and practical conditions and their effects on the blowing length of the optical fiber within the network. The proposed model considers the equipment providers indications as some theoretical ones, characterized by absolutely linear motion and parallel position of the optical fibers. This ideal situation is verified by the model. In practice, any exception from these hypotheses produces a shortening of the length of penetration. The paper emphases the reasons of differences between the optical fiber penetration lengths observed in practical situation of communication networks and the penetration length indicated by the equipment providers.