Fault tolerance in sensor networks using self-diagnosing sensor nodes

This paper describes a method of introducing a level of fault tolerance into wireless sensor networks by monitoring the status of each wireless sensor node. We focus on the detection of physical malfunctions, caused by impacts or incorrect orientation. We design a flexible circuit using accelerometers that acts as a sensing layer around a node, which will be capable of sensing the physical condition of a node. Software analysis is performed on the raw data from the accelerometers to determine the orientation of the node and to detect impacts. The information from the analysis enables us to assess the damage probability. After detecting that a node is not healthy, the effect this has on the whole sensor network is looked at. We explore the changes that can be required such as treating sensor readings as invalid. At the network level, the routing protocol should be made aware of faulty nodes to ensure that faulty nodes are routed around.