Improving Energy Efficiency and Network Lifetime in IoT Systems: A Novel Theoretical Framework and Experimental Validation

Abstract

The Internet of Things (IoT) integrates devices, sensors and actuators into a unified network that delivers a range of services to end-users through internet connectivity. Over the past decade, the demand for IoT devices has surged due to their ability to simplify and enhance everyday activities. However, maintaining network stability and optimising performance in IoT systems involves addressing several key factors, such as power consumption, cost, bandwidth, data rate and processing time. Despite significant advancements in IoT research, there is still a notable gap in comprehensive studies on reducing energy consumption across the diverse layers and components of IoT systems. This research addresses the need for an integrated framework to enhance power efficiency in IoT environments by focusing on five critical areas: IoT architecture, communication technologies, IoT application types, IoT application protocols, and overall challenges faced by IoT networks. The thesis presents three innovative approaches designed to improve the energy efficiency and network lifetime of IoT systems. The first approach introduces the constrained application protocol 45 (CoAP45), an enhanced protocol that minimises CPU usage by optimising server update mechanisms and thus reducing energy consumption for resource-constrained IoT nodes. The second approach, the mist fuzzy healthcare system (MFHS), leverages mist computing and fuzzy logic to reduce processing time and energy consumption by pre-allocating resources based on real-time data categorisation, significantly improving healthcare IoT applications. The third approach, the IoT-mist bat algorithm (IMBA), uses bio-inspired optimisation techniques to dynamically allocate resources in complex IoT environments, enhancing load distribution, task completion rate and energy efficiency. Extensive experimental evaluations demonstrate that these three approaches successfully extend the operational lifetime of IoT networks while reducing power consumption and processing delays. The results indicate that CoAP45, MFHS and IMBA provide viable solutions for addressing the limitations of existing protocols and frameworks, thereby contributing to more sustainable and effective IoT systems. This research offers a novel theoretical and practical framework for future studies aiming to optimise energy efficiency in IoT networks, with potential applications in healthcare, industrial automation, and smart city environments.