Optimal diverse routing in telecommunication fiber networks

Telecommunication fiber networks can be more complicated than the traditional graph-theoretic networks of nodes and links. This is due to practical and economic considerations. The paper considers two major types of deviations from the traditional graph-theoretic network, and provide an algorithm for the shortest pair of physically-disjoint paths between a given pair of nodes in the network. Such disjoint paths can be used for improving the reliability of the network, e.g., one path may be used as a back up while the other is actually used for transmission of data. Alternatively, the entire traffic between the given pair of nodes in the network may be divided equally over the two disjoint paths so that if a node or link on one of the paths fails, not all of the traffic is lost. Optimizing the length of disjoint paths helps in reducing the amount of fiber usage and network costs