Bifurcation in Transmission Networks Under Variation of Link Capacity

Much research attention has been devoted to the investigation of how the structure of a network affects its intended performance. However, conclusions drawn from the previous studies are often inconsistent and even contradictory. In order to identify the causes of these diverse results and to explore the impact of network topology on performance, we apply the concept of bifurcation in dynamical systems and consider the effect of varying a crucial parameter for networks of different structures. In this paper, we study transmission networks and identify the capacity setting as the parameter. Upon varying this parameter, the behavioral change of the network is observed. Specifically, we focus on communication networks and power grids, and study the improvement or degradation of robustness of such networks under variation of link capacity. We observe that the effect of increasing link capacity on robustness differs for different networks, and a bifurcation point exists in some cases which divides regions of opposite robustness behavior. Our work demonstrates that capacity settings play a crucially important role in determining how network structure affects the intended performance of transmission networks, and clarifies the previous reported contradictory results.