Reliable Network Design Considering Cost to Decrease Failure Probability of Simultaneous Failure

Abstract

It is important to design a reliable information network that is resistant to network failures. Protection to decrease failure probability by both backup mechanism and fast recovery mechanism is an approach to design such an information network. However, enormous cost is required, if the failure probability of all network elements must be decreased. Therefore, it is practical to preferentially protect only some highly required network elements so that the reliability of the entire information network is improved. In this paper, we assume that the failure probability of a failure set, a set of network elements that simultaneously fails at a single disaster, can be decreased according to cost for protection. Since failure probability of each failure set is decreased according to cost assigned to the failure set, the network failure probability defined as the probability that the entire information network is not connected, is decreased. We define a network design problem that determines cost assigned to each failure set so that the sum of the cost assigned to each failure set is minimized under the constraint that the network failure probability must be within a threshold. First, we formulate the network design problem as a 0–1 integer programming problem, when the relationship between cost and probability decreased according to cost is a step function. In addition, we evaluate the performance by using the topology of some actual information networks.