Robustness of Complex Communication Networks under Rewiring Operations

Recent researches on complex networks show that some most important communications systems, including Internet and World-Wide Web (WWW), are scale-free networks with power-law nodal-degree distributions. It is claimed that such networks are robust under random failure yet fragile under intentional attack that takes down network nodes in a decreasing order of their degrees. In this paper, we show that different scale-free networks with exactly the same degree of every node (where one of them could be achieved by rewiring some links in the others) can have different tolerances to the intentional attack. This observation is important in two aspects: (i) It demonstrates that nodal-degree distribution does not define network robustness solely by itself. Additional measures are needed to take other factors into consideration; and (ii) It reveals new possibilities of developing protection strategies against the intentional attack