Fault-Tolerant Clustering Topology Evolution Mechanism of Wireless Sensor Networks

Wireless sensor networks (WSNs) are often subject to failures caused by energy depletion, software or hardware fault of nodes, environmental events, hostile attacks, and other reasons. It is critical to ensure a WSN application system is available during some presence of fault or interruption. Recent work in topology control has shown that a reasonable topology can improve the robustness of WSN. However, due to the limited resource of sensor nodes, topology control cannot easily tradeoff between fault tolerance and energy saving. To address this issue, we present a regular hexagonal-based clustering scheme (RHCS) and a scale-free topology evolution mechanism (SFTEM) for WSNs, which increases network survivability as well as maintains energy balance. RHCS uses a regular hexagonal structure for clustering sensor nodes, which satisfies at least 1-coverage fault-tolerance. SFTEM combines the reliability of RHCS with scale-free properties to connect clusters to form a robust WSN, which exploits the synergy between reliable clustering scheme and topology evolution, and can tolerate comprehensive faults including random failure and energy failure. In addition, to evaluate the performance of SFTEM, the simulation experiments were carried out to compare three factors including fault-tolerance, intrusion-tolerance, and energy balance with other methods in literature. The simulation results show that, the performance of SFTEM is superior to those of the referenced topology evolution mechanisms of WSNs.