Energy-Efficient Cluster-Based Scheme for Handling Node Failure in Real-Time Sensor Networks

Wireless sensor networks are characterized by dense deployment of energy constrained nodes. Owing to the deployment of large number of sensor nodes in uncontrolled hostile or harsh environments and unmonitored operation, it is common that a node becomes inactive due to a node failure or exhaustion of the respective energy resource. Such node failures result in the reduction of the cluster quality of service (Qos). This problem becomes more complex when the services in the wireless sensor network (WSN) are real-time. To avoid the degradation of QoS, it is necessary that the failures be recovered using a proper method. In this paper, we present a dynamic energy efficient real-time job allocation algorithm called ERTJA for handling such node failures in a cluster. ERTJA relies on the other cluster nodes to handle the node failure. It tries to minimize the energy consumption of the cluster by minimal activation of the sleeping nodes, while guaranteeing the QoS of the cluster application. Further, when the number of sleeping nodes is limited, the proposed algorithm uses the idle times of the existing nodes to have a graceful QoS degradation of the cluster QoS upon the node failure. Simulation results show significant performance improvements of ERTJA in terms of energy consumption comparing to the N-EDF-Plus algorithm. According to the results, ERTJA can save up to 27.2% of the cluster energy consumption with respect to N-EDF-Plus.