Coverage-connectivity based fault tolerance procedure in wireless sensor networks

In this paper, we propose a new approach to ensure fault tolerance in wireless sensor networks (WSNs) while guaranteeing both coverage and connectivity in the network. Hence after reviewing the fault tolerance related works in wireless sensor networks and enumerating the requirements that must be satisfied by our fault tolerance solution, we present the different mechanisms we propose to maintain both coverage and connectivity in the network in the case of node failure. Our approach is a proactive one in the sense that it aims to replace the “up to fail” node before its defection. In the case of impossible replacement of the “up to fail” node, a fast rerouting mechanism is proposed to forward the traffic initially routed via the “up to fail” node. Performance evaluation of our fault tolerance approach shows that the number of nodes potentially eligible for the “up to fail” node replacement depends on a threshold about the node redundancy as well as the network density metric. Moreover, we show that, compared to a classical routing algorithm, our fast rerouting mechanism reduces the packet loss rate in the network.