Evaluating geographic topological vulnerabilities

Measuring the survivability of core backbone communication networks to geographic correlated failures is important in network analysis and design. Different measures of network survivability have been used in the literature, for example, Algebraic Connectivity, Network Criticality, Average Shortest Path, Network Diameter, Node Degree and Node Strength. This paper proposes a new performance measure Weighted Spectrum to evaluate network survivability regarding geographic correlated failures. Further we conduct a comparative analysis by finding the most vulnerable geographic cuts or nodes in the network though solving an optimization problem to determine the cut with the largest impact for each measure. Numerical results on several sample network topologies show that the worst-case geographic cuts depend on the measure used in an unweighted graph. The proposed Weighted Spectrum measure is shown to be more versatile than other measures in unweighted and weighted graphs.