A Hierarchical Fog Computing Framework for Low-Latency Data Processing in Smart City IoT Systems

Abstract

The rapid proliferation of Internet of Things (IoT) technologies has accelerated the evolution of smart cities by enabling intelligent services across transportation, healthcare, environmental monitoring, public safety, and energy management. However, the massive volume and heterogeneous nature of IoT-generated data impose significant challenges on conventional cloud-centric architectures, particularly in terms of communication latency, bandwidth consumption, scalability, and real-time responsiveness. These limitations reduce the effectiveness of latency-sensitive applications that require immediate data processing and decision-making. To address these challenges, this study proposes a hierarchical fog computing framework for low-latency data processing in smart city IoT systems. The proposed framework adopts a three-layer architecture comprising the IoT layer, the fog layer, and the cloud layer. IoT devices continuously collect real-time data, fog nodes perform localized processing, filtering, and time-critical decision-making, while cloud servers execute large-scale analytics, long-term storage, and computationally intensive tasks. This hierarchical distribution of computational workloads enables data to be processed closer to its source, thereby reducing unnecessary communication with centralized cloud infrastructures. The proposed framework is conceptually evaluated based on key performance criteria, including end-to-end latency, bandwidth utilization, scalability, resource utilization, and service reliability. The analysis indicates that hierarchical fog computing can substantially improve the responsiveness of smart city services by minimizing communication delays, reducing network congestion, and enabling efficient collaboration between distributed fog nodes and centralized cloud resources. The findings demonstrate that hierarchical fog computing provides a scalable and efficient foundation for next-generation smart city infrastructures while complementing conventional cloud computing. Future research should focus on experimental validation, intelligent resource management, cybersecurity, and the integration of artificial intelligence with emerging communication technologies, including 5G and beyond.