Sensitivity of the resilience of congested random networks to rolloff and offset in truncated power-law degree distributions

Random networks were generated with the random configuration model with prescribed truncated power-law degree distributions, parameterized by an exponent, an offset, and an exponential rolloff. As a model of an attack, each network had exactly one of its highest degree nodes removed, with the result that in some cases, one or more remaining nodes became congested with the reassignment of the load. The congested nodes were then removed, and the ‘‘cascade failure’’ process continued until all nodes were uncongested. The ratio of the number of nodes of the largest remaining cluster to the number of nodes in the original network was taken to be a measure of the network’s resiliency to highest-degree node removal. We found that the resiliency is sensitive to both rolloff and offset (but not to cutoff) in the degree distribution, and that rolloff tends to decrease resiliency while offset tends to increase it. r 2006 Elsevier B.V. All rights reserved. PACS: 89.75. k; 89.75.Da; 89.75.Fb; 89.75.Hc