Interlayer Coupling Strategy for Two-Layer Interdependent Command-and-Control Networks: Balancing Node Walk Betweenness and Operational Attributes

In system-of-systems operations, command-and-control networks (C2Ns) increasingly exhibit hierarchical interdependence and cross-network coupling. Designing effective interlayer coupling strategies is therefore essential for improving the survivability of interdependent C2Ns under attacks. However, most existing coupling strategies are predominantly topology-driven and fail to jointly capture multipath information transmission characteristics and operational compatibility among heterogeneous nodes. To address this issue, this study proposes an interlayer coupling strategy for two-layer interdependent C2Ns, referred to as PRO, by integrating node walk betweenness and operational attributes. Specifically, a walk-betweenness-based dependency strength metric is constructed to characterize node importance from the perspective of multipath information transmission, while an operational attribute matching mechanism is introduced to evaluate the functional compatibility of cross-layer nodes. Based on these two components, the PRO strategy is developed for survivability-oriented interlayer coupling design. Simulation experiments on an air-defense command-and-control scenario are conducted under both deliberate and random attacks. The results of repeated simulations show that the proposed strategy consistently outperforms the compared baseline methods in node survival rate, observe-orient-decide-act (OODA)-oriented functional chain retention ratio, and combat link efficiency degradation rate. Compared with the baseline random strategy, under random attack, PRO improves node survival rate by 50.00%, improves the OODA-oriented functional chain retention ratio by 19.40%, and reduces the combat link efficiency degradation rate by 3.53%. These results indicate that the PRO strategy improves not only structural robustness but also the preservation of sensing–command–firepower coordination under cascading failures. The proposed method provides a joint structural–functional framework for mitigating cascading failure risks and enhancing survivability in interdependent C2Ns.