🤖 AI Summary
To address the challenges of acquiring dynamic origin-destination (OD) matrices in urban traffic planning—namely, low accuracy, high cost, and limited temporal resolution—this paper proposes a novel fine-grained mobility sensing paradigm leveraging cellular network signaling data. We formulate anonymized signaling sequences as spatiotemporal graph event streams and design a lightweight trajectory reconstruction algorithm coupled with regional flow tensor decomposition, overcoming bottlenecks imposed by GPS sparsity and privacy constraints. Our framework integrates spatiotemporal graph neural networks, self-supervised trajectory completion, and multi-scale tensor decomposition, augmented by a differential privacy-enhanced aggregation mechanism. Evaluated across three megacities, the approach generates minute-level OD matrices with 37% lower prediction error than conventional models and fivefold improvement in decision-making latency. The resulting infrastructure enables scalable, real-time, and privacy-preserving support for low-carbon and intelligent urban traffic governance.