Service-Aware Criticality Assessment of Inter-Satellite Links in LEO Satellite Networks

Low-Earth-Orbit (LEO) satellite networks are essential infrastructure for global broadband services. However, their time-varying topology and non-uniform ground traffic distribution hinder traditional centrality-based methods from identifying service-critical inter-satellite links. This paper proposes a Service-Aware Link Criticality (SALC) framework. An event-driven temporal graph and a gravity model capture topology dynamics and traffic distribution. Three complementary metrics are designed: weighted coverage contribution, multipath traffic allocation, and vulnerability propagation potential. These metrics assess link failures from the aspects of coverage, traffic, and delay, respectively. A CRITIC-entropy hybrid weighting method and TOPSIS produce a unified criticality ranking. Experiments on Starlink data show that SALC outperforms baseline methods. It also detects critical links missed by topology-based approaches, confirming its effectiveness.