ENHANCING SUSTAINABILITY IN WIRELESS SENSOR NETWORKS THROUGH PSO-BASED CLUSTER OPTIMIZATION AND ADAPTIVE SINK MOBILITY

Wireless Sensor Networks (WSNs) represent a fundamental part of current Internet of Things (IoT) systems, allowing for constant monitoring in smart cities, the environment, and industrial systems. However, a fundamental limitation of these networks over long-term operation is uneven energy consumption and the energy-hole problem that arises around a static sink. To address these issues, this paper presents PSO-MSM, a sustainability-oriented communication protocol that combines multi-objective Particle Swarm Optimization (PSO) and adaptive mobile sink mobility. The protocol optimizes cluster head (CH) selection and dynamically adjusts the sink’s trajectory through multi-radius circular paths to balance the forwarding load across the sensing field. Optimization is performed jointly with consideration of residual energy, intra-cluster compactness, and the proximity of each CH to the sink. This coordinated clustering-mobility design reduces long-distance transmissions, relieves hotspot depletion, and improves overall energy sustainability. Extensive ns-3 simulations demonstrate that PSO-MSM significantly enhances network lifetime, increasing the time to first-node-dead, half-nodes-dead, and last-node-dead events by 46% compared with LEACH, HEED, and PEGASIS. The protocol also achieves higher residual energy, improved packet delivery ratio, reduced end-to-end delay, decreased channel congestion, and significantly lower energy imbalance. These results indicate that PSO-MSM provides an effective solution for smart city and IoT deployments, offering reliability, reduced maintenance, and improved sustainability for long-term operations where these issues are a major priority.