Dynamic Clustering-Based Time Synchronization for PLC-TWACS Integrated Multimodal Power IoT in Smart Park

Power Internet of Things devices deployed in smart parks have strict time synchronization requirements. However, due to the limited availability of 4-G/5-G, optical fiber, and satellite, how to achieve low-cost, reliable, and efficient time synchronization based on existing power line carrier (PLC) and two-way power frequency automatic communication system (TWACS) integrated multimodal communication has become a key challenge. Motivated by this, a cluster-based time synchronization network structure is proposed that seamlessly integrates PLC and TWACS, which provides an accurate synchronization model by comprehensively considering frequency offset, timestamp recorded error, timestamp jitter error, and transmission delay. Moreover, we incorporate digital phase-locked loop to compensate synchronization error by correcting frequency offset in clusters. The goal is to realize the minimization of the average time synchronization error within clusters. To achieve this goal, we introduce a coalition formation game-based dynamic clustering algorithm (CFG-DC), designed to effectively address the proposed optimization challenge. CFG-DC achieves dynamic clustering with consideration of time synchronization error awareness by performing leave-and-join decision iteratively to maximize synchronization error-based utility function. Simulation distinctly demonstrate the remarkable achievement of CFG-DC in attaining heightened levels of accuracy in time synchronization.