Analysis of relay node failure in heterogeneous wireless sensor networks

Introduction: Fault tolerance is an important issue for assuring data reliability, energy saving and prolonging the lifetime of wireless sensor networks. Since, sensor node, relay node, etc. are prone to failure, there is a need an effective fault tolerance mechanism. Method: Relay nodes have used as cluster heads and the concept of two disjoint paths has used for proving fault tolerance against link failure. To evaluate the Fault Tolerance Level, Mean Time to Failure and subsequently Failure Rate has calculated, that reflect the reliability of the network. Results: The results show that as the area size of the network increases, the average Fault Tolerance Level of the network almost becomes constant. Furthermore, when the Mean Time to Failure of the network decreases then the Failure Rate increases. It means the overall reliability of the network with smaller network size is more than the larger network size. Conclusion: This analysis helps the network designers to decide the quantity of deployment of relay nodes with respect to fault tolerance level. It also, may help to prevent relay nodes failure as to take appropriate action so as to increase the fault tolerance level of the network as well as network reliability. Discussion: This paper presents a detailed analysis of relay nodes failure under distinct network configurations in heterogeneous wireless sensor networks.