Modeling and Optimization of Parallel and Distributed Embedded Systems

Chapter 4Modeling and Analysis of Fault Detection and Fault Tolerance in Embedded Wireless Sensor Networks^*

Wireless sensor networks (WSNs) consist of spatially distributed autonomous sensor nodes that collaborate with each other to perform an application task. A sensor node comprises a sensing unit (a sensing unit contains sensors such as temperature and humidity sensors), a processing unit, a storage unit, a communication unit, a power unit, an actuator unit, and an optional location finding unit [44].

Figure 4.1 shows the WSN architecture that we consider in this chapter [81–83]. The sensor nodes distributed in the sensor field gather information (sensed data or statistics) about an observed phenomenon (e.g., environment, target) using attached sensors. A group of sensor nodes, located geographically close to each other, is called a WSN cluster. Each WSN cluster has one cluster head (WSN cluster formation, and cluster head determination/maintenance is beyond the scope of this chapter). Sensed data within a WSN cluster is collected by the cluster head and is relayed to a sink node (or base station) via the sensor nodes' ad hoc network. The sink node transmits the received information back to the WSN designer and/or WSN manager via a gateway node connected to a computer network. The WSN designer is responsible for designing the WSN for a particular application to meet application requirements such as lifetime, reliability, and throughput. After WSN design and deployment, the ...