π€ AI Summary
This work addresses the challenge that multimodal graph data are often inaccessible due to privacy and commercial constraints, while existing federated graph learning approaches fail to effectively tackle the unique difficulties of multimodal federated graph learning (MMFGL). To bridge this gap, the paper presents the first systematic formulation of the MMFGL paradigm and introduces MM-OpenFGL, the first comprehensive benchmark for this setting. MM-OpenFGL encompasses 19 datasets, 8 simulation strategies, 6 tasks, and 57 methods, offering a modular API that uniformly supports key components including multimodal modeling, federated protocols, heterogeneous alignment, and topology simulation. Extensive experiments validate the frameworkβs necessity, effectiveness, robustness, and efficiency, thereby establishing a foundational resource that fills a critical void in systematic MMFGL research and paves the way for future advancements.
π Abstract
Multimodal-attributed graphs (MMAGs) provide a unified framework for modeling complex relational data by integrating heterogeneous modalities with graph structures. While centralized learning has shown promising performance, MMAGs in real-world applications are often distributed across isolated platforms and cannot be shared due to privacy concerns or commercial constraints. Federated graph learning (FGL) offers a natural solution for collaborative training under such settings; however, existing studies largely focus on single-modality graphs and do not adequately address the challenges unique to multimodal federated graph learning (MMFGL). To bridge this gap, we present MM-OpenFGL, the first comprehensive benchmark that systematically formalizes the MMFGL paradigm and enables rigorous evaluation. MM-OpenFGL comprises 19 multimodal datasets spanning 7 application domains, 8 simulation strategies capturing modality and topology variations, 6 downstream tasks, and 57 state-of-the-art methods implemented through a modular API. Extensive experiments investigate MMFGL from the perspectives of necessity, effectiveness, robustness, and efficiency, offering valuable insights for future research on MMFGL.