DAiMo: Motif Density Enhances Topology Robustness for Highly Dynamic Scale-Free IoT

Robust Topology is a key prerequisite to providing consistent connectivity for highly dynamic Internet-of-Things (IoT) applications that are suffering node failures. In this paper, we present a two-step approach to organizing the most robust IoT topology. First, we propose a novel robustness metric denoted as <inline-formula><tex-math notation="LaTeX">$I$</tex-math></inline-formula>, which is based on network motifs and is specifically designed to sensitively analyze the dynamic changes in topology resulting from node failures. Second, we introduce a Distributed duAl-layer collaborative competition optimization strategy based on Motif density (DAiMo). This strategy significantly expands the search space for optimal solutions and facilitates the identification of the optimal IoT topology. We utilize the motif density concept in the collaborative optimization process to efficiently search for the optimal topology. To support our approach, extensive mathematical proofs are provided to demonstrate the advantages of the metric <inline-formula><tex-math notation="LaTeX">$I$</tex-math></inline-formula> in effectively perceiving changes in IoT topology and to establish the convergence of the DAiMo algorithm. Finally, we conduct comprehensive performance evaluations of DAiMo and investigate the influence of network motifs on the resilience and reliability of IoT topologies. Experimental results clearly indicate that the proposed method outperforms existing state-of-the-art topology optimization methods in terms of enhancing network robustness.