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

This chapter highlights fault diagnosis in wireless sensor networks (WSNs) through various fault detection algorithms. It first presents simulation of fault detection algorithms using ns-2 to determine the algorithms' accuracy and false alarm rates. The chapter then analyzes the effectiveness of fault detection algorithms under conditions modeled from the real-world data. It proposes a fault tolerance (FT) sensor node model consisting of duplex sensors (i.e., one active sensor and one inactive spare sensor) that exploits the synergy of fault detection and FT. Next, FT parameters, such as coverage factor, are characterized by exploiting the synergy between fault detection and FT. The chapter also proposes hierarchical Markov models to characterize WSN reliability and mean time to failure (MTTF). In addition, iso-MTTF (isoreliability) for WSN clusters is determined. Finally, the chapter reviews research challenges and future research directions for the design and deployment of reliable and trustworthy WSNs.