Internet of Things-Based Smart Parking Systems: An Integrative Review of Architectures, Technologies and Deployment Challenges
Rapid urbanisation, increasing vehicle ownership and inefficient parking operations have intensified search traffic, congestion and underutilisation of parking resources. This paper presents an integrative review of Internet of Things (IoT)-based smart parking systems, with emphasis on architecture, enabling technologies, operational requirements and deployment in resource-constrained environments. A transparent search and thematic-synthesis procedure was applied to 28 sources comprising 24 peer-reviewed publications and four recognised technical standards. Evidence was extracted on sensing and identification, communication, edge-fog-cloud processing, application services, security, performance evaluation and implementation constraints. The synthesis shows that reliable smart parking is not produced by a sensor or mobile application alone; it depends on coordinated responsibilities across six layers: perception and identification, edge and gateway processing, communication, platform and data management, application services, and security and governance. Ultrasonic, magnetic, infrared, inductive and camera-based methods provide different trade-offs in accuracy, coverage, energy demand, privacy and lifecycle cost. Wi-Fi and ZigBee are suited to bound facilities, while LoRaWAN and NB-IoT support dispersed low-power deployments. Edge and fog processing improve responsiveness and continuity, whereas cloud services support historical analysis and multi-site management. The review identifies persistent weaknesses in short-term prototype evaluation, cybersecurity, interoperability, maintenance planning, cost reporting and evidence from African cities. A phased, context-sensitive deployment framework and a multidimensional evaluation set are proposed for campuses, hospitals, commercial facilities and municipal parking environments.