Shortest node-disjoint path using dual-network topology in optical switched networks

This paper presents a new method for finding shortest node-disjoint paths in optical-switched networks with no wavelength conversion. The proposed method is based on a modified version of Dijkstra algorithm that works on an expanded so-called dual-network topology with n×n- nodes and 2×m×n links, where n is the number of nodes and m is the number of links in the original network. Despite the larger network size, the execution time of the algorithm is in polynomial order (mn + n ² log n). Considering that the problem is NP-complete, the presented algorithm takes much less time than using ILP, which takes exponential time. Yet, it is able to find all available disjoint paths obtainable by ILP.