SEP (A Stable Election Protocol) in Wireless Sensor Network

SEP: A Stable Election Protocol for clustered heterogeneous wireless sensor networks

This study examines how the energy heterogeneity of nodes affects the dynamics of hierarchically clustered wireless sensor networks. In such networks, selected nodes act as cluster heads, gathering and forwarding their cluster members' data to the sink. We consider a scenario where a subset of sensor nodes possesses additional energy resources, introducing a layer of heterogeneity that might arise from initial deployment strategies or evolve during network operation. Assuming a uniform and static distribution of sensors, along with predefined sink location and sensor field dimensions, we observe that network stability significantly declines following the demise of the first node, a situation exacerbated by node heterogeneity. Traditional clustering protocols, which treat all nodes as energy equals, fail to capitalize on this heterogeneity. To address this, we introduce the Stable Election Protocol (SEP), designed to extend the period until the first node failure—a critical factor for applications dependent on consistent sensor network feedback. SEP employs weighted election probabilities for cluster head selection, based on each node's residual energy, to enhance network stability. Simulation results demonstrate that SEP consistently extends the stability period and improves average throughput compared to existing clustering protocols. Further analysis on SEP's response to various levels of energy imbalance among nodes reveals that greater energy contributions from more capable nodes lead to an extended stability period, highlighting the protocol's effectiveness in leveraging node heterogeneity.