ONCP: an optimised node clustering protocol using PSO for enhanced multimedia IoT network performance

High-performance and reliable multimedia communication is critical for modern Internet of Things (IoT) applications such as smart healthcare, wearables, homes, and industrial automation. Cross-layer protocol designs have emerged to improve network performance by enabling coordination across protocol layers. The Internet of Medical Things (IoMT) protocol applies cross-layer optimisation to reduce energy usage and latency but faces scalability and real-time issues in dense networks due to increased computational complexity. To address this, enhancements like directional antennas and the dual sensing MAC (DSDMAC) protocol were introduced at the medium access control (MAC) layer to improve channel access and reduce hidden terminal issues, forming the basis for the MAC cross layer communication protocol (MCROSS). Building on this, the optimised node clustering protocol (ONCP) introduces a modified PSO-based clustering method for intelligent selection of cluster heads and relay nodes. It uses a fitness function that considers multiple parameters (packet forwarding rate (PFR), residual or remaining energy rate (RER), congestion rate (CR)), resulting in improved energy efficiency, load balancing, and reliability. Comparative analysis confirms ONCP's superior performance across diverse metrics.