Architectural enhancements, challenges and future trends in real-time IoT applications over 5G networks

The introduction of real-time Internet of Things (IoT) applications has introduced unprecedented demands on communication systems, which require ultra-low latency, high reliability, and massive device connectivity. Fifth-generation (5G) wireless networks represent a foundational shift in network architecture, offering advanced capabilities such as ultra-reliable low-latency communication (URLLC), mobile edge computing (MEC), and network slicing to support time-sensitive IoT services at scale. This review critically examines how these architectural enhancements enable real-time IoT deployment across domains, with inclusion of autonomous transportation, industrial automation, remote healthcare, and smart energy systems. While 5G provides a robust framework, its real-world adoption has faced technical constraints related to interoperability, spectrum management, energy efficiency, and cybersecurity. The paper synthesizes existing research on these challenges, and highlight persistent integration gaps and trade-offs that must be navigated to achieve deterministic performance in complex environments. In response, future research directions are proposed, including AI-driven orchestration, blockchain-based trust models, and emerging sixth-generation (6G) technologies. This work provides a comprehensive foundation for scalable, secure, and latency-guaranteed designs of real-time IoT systems in the 5G era and beyond.