DA-MC-SEP: a distance-aware multi-hop clustering and stable election protocol for heterogeneous WSNs

Abstract Wireless Sensor Networks (WSNs) consist of large numbers of sensor nodes (SNs) operating under strict energy constraints, making efficient routing protocols essential for extending network lifetime and ensuring reliable data delivery. This paper introduces a Distance-Aware Multi-Hop Clustering and Stable Election Protocol for heterogeneous WSNs (DA-MC-SEP). The proposed protocol enhances energy efficiency by integrating multi-level energy heterogeneity, distance awareness, and a hybrid single-hop and multi-hop communication strategy. The network is divided into predefined cluster regions supported by Leader Cluster Heads (LCHs), which assist distant SNs and Cluster Heads (CHs) in forwarding aggregated data, thereby reducing long-range transmissions and preventing premature energy depletion. DA-MC-SEP also incorporates both energy and distance factors into an improved threshold-based CH-election strategy, granting higher CH-election priority to SNs with higher energy and shorter distances to the Base Station (BS). To avoid unnecessary cluster formation, the protocol also considers the average network energy during the CH-selection process. Consequently, it aims to reduce transmission power loss, balance energy consumption, and mitigate CH overload under the considered network model. Simulation results indicate that, in the evaluated scenarios, DA-MC-SEP demonstrates improved performance compared to clustering-based protocols such as SEP, Imp-LEACH, DARE-SEP, and EEMCL. Improvements are particularly evident in total network lifetime, stability period (first-node death), half-node death, last-node death, throughput, packet delivery ratio (PDR), normalized residual energy, and standard deviation of node energy, indicating more balanced energy consumption across the network. Numerical analysis further reveals that DA-MC-SEP can achieve up to 30% improvement in network lifetime and throughput relative to the baseline protocols.