IF: isolating fault nodes with mobile scanner

Fault diagnosis plays an important role on stable applications maintaining in wireless sensor networks WSNs. Most existing researchers are concerned about the statics nodes-based diagnosis techniques, which are incompetent to cope with those dynamically occurring faults. In this paper, we propose a novel mechanism isolating fault IF nodes that employs the mobile node as a scanner to diagnose the faults in WSNs. The mobile scanner can detect the fault nodes within its communication region by using sniffer. It can also control the transmitting route of nodes by modifying their links. Starting from the base station, the mobile scanner periodically selects and visits all monitoring stations and consequently explores all static nodes in the monitoring area. After detecting a fault node, the mobile scanner will prevent it from connecting to the other normal nodes. We aim at finding the least number of monitoring stations and discovering an optimal route. We first formulate the two research issues to hitting set problem and travel salesperson problem. We then solve these two nondeterministic polynomial time hard problems by proposing an approximate algorithm, weighted, and hierarchical IF, which only uses local information. The mobile scanner makes a decision by weighing both the significance and the priority of nodes level by level. The proposed mechanism IF maintains the stabile service of WSNs in a transparent manner. The simulation results show that our algorithm can effectively isolate fault nodes, alleviate the damages of network corrupting, and hence increase the resilience of WSNs. Copyright © 2013 John Wiley & Sons, Ltd.