On Maximizing Reliability of Network Topology Design Using a Practical Dynamic Programming Approach

This paper addresses an NP-complete problem of designing a network topology (NT) with the maximum 2-terminal reliability (R) subject to a cost constraint (C). More specifically, given the locations of the various computer centers (nodes), their connecting links, each link’s reliability and cost, and the maximum budget cost to install the links, the NT design problem, called NTD-RC, aims to find an NT that has the maximum reliability with cost within the budget. Since cost is a major issue in NT design, NTD-RC is applicable for critical applications requiring maximized reliability. This paper formulates a dynamic programming (DP) scheme to help solve NTD-RC. A DP approach, called Algo-DP, finds the set of links to be deleted from the original network to obtain an optimal NT. The paper proposes five-link ordering criteria to improve the performance of Algo-DP. Simulation results on different benchmark networks of various sizes are used to compare Algo-DP with existing techniques in the literature and show the merits of using the sorting methods, and the effectiveness of our algorithm. We found that Algo-DP generates NT with the same or better 2-terminal reliability measure (with up to 4.3% improvement) on 92% of the network topologies. Results indicate Algo-DP demonstrated better performance than other existing algorithm. Furthermore, Algo-DP shows that it is computationally more efficient compared to the recent existing approach.