Will the deepening of interdependence network coupling increase the robustness of the network?

Modern networks are increasingly interdependent, with a typical example being the coupling relationship between communication networks and power networks. As smart grids evolve and coupling intensifies, the overall security of the networks faces significant challenges. Some real-world cases have indicated that increasing the coupling strength between networks may increase the vulnerability of networks to failures. Many researchers have studied the coupling relationship in interdependent networks from various perspectives, including modeling the coupling relationship, considering load flow and developing strategies for failure mitigation and recovery. However, there is currently limited research on the specific effects of coupling strength on network robustness. This paper focuses on the interdependence between communication networks and modern power grids and investigates the influence of coupling strength on network robustness by constructing a cascading failure model. Through simulations on power-communication networks, three main conclusions are drawn: (1) Deepening the coupling strength does not necessarily increase network robustness; in some cases, excessive coupling can decrease the network’s robustness to cascading failures. (2) Timely adjustment of the mode of adding coupling links is beneficial for enhancing network robustness. (3) An abnormal phenomenon is observed where network robustness decreases as the capacity parameter [Formula: see text] increases.