Modeling and Analyzing the Cascading Invulnerability of Wireless Sensor Networks

Current research on cascading model for wireless sensor networks (WSNs) fails to consider the impacts of the sink node on network traffic distribution, which makes them unable to properly reflect the sink-convergence feature of WSNs. In this paper, we build a more practical cascading model for WSNs, in which the load function is defined on each node according to a new traffic metric directional betweenness, and the overload function is defined according to the congested state of each node. In addition, the failed node can recover via reboot after a certain time delay rather than being permanently removed from the network. Simulation results show that the network invulnerability is positively correlated with the overload-tolerance coefficient and negatively correlated with the congestion-tolerance coefficient, and the extension of the recovery time will exacerbate the fluctuation of the cascading process. Moreover, placing the sink node close to the center of the deployment area can contribute to the network invulnerability.