INTERNET OF THINGS IN SMART ENVIRONMENTS: ARCHITECTURE, PROTOCOLS, SECURITY, AND EMERGING RESEARCH CHALLENGES

Abstract

The Internet of Things (IoT) technology represents one of the paradigm-shifting innovations of the twenty-first century and makes possible the interaction of billions of disparate hardware elements with each other seamlessly and efficiently, whether within smart homes, industrial facilities, healthcare organizations, or citywide infrastructure. Notwithstanding the breakthrough advancements in miniaturized hardware design, wireless communications protocols, and cloud technologies, the deployment of the vast IoT infrastructures is still plagued by inherent limitations in terms of power consumption, interoperability, scalability, latency, and security concerns. This work reviews the architecture of IoT systems and studies its major aspects, such as the perception–network–application triad, nodes' hardware pecifications, communication protocols (MQTT, CoAP, LoRaWAN, NB-IoT, ZigBee), network topologies, data flow architecture from edge through fog to cloud, and the IoT protocol stack. A protocol latency performance comparison is conducted using simulation along with energy consumption versus distance and throughput under different node density scenarios. Eight potential security threats are described along with proposed mitigation strategies and a defense-in-depth approach. Finally, five important areas that need further research are specified.

Keywords : Internet of Things, IoT architecture, MQTT, LoRaWAN, edge computing, fog computing, network topology, IoT security, smart systems, 5G NB-IoT, energy harvesting, digital twin