Fault Tolerant Distributed Sensor Networks

Abstract

Fault tolerant computer systems are systems designed around the concepts of fault tolerance. In essence, they must be able to continue working to a level of satisfaction in the presence of faults. Fault tolerance is not just a property of individual machines; it may also characterize the rules by which they interact. The concept of fault tolerance plays a key role in distributed sensor networks as it is very crucial that sensors do their sensing job as a group even when one or a number of them become faulty. Sensors that supply data to computer systems are inherently unreliable. When sensors are distributed, reliability is further compromised. How can a system tell good sensor data from faulty? In this chapter, we focus on Fault tolerant sensor networks. First, we introduce Byzantine generals problem as an example of agreement problem in Byzantine army. Then, we discuss Byzantine fault tolerance which is the resistance of a fault tolerant computer system, particularly distributed computing systems, towards electronic component failures where there is imperfect information on whether a component is failed. Afterwards, we address fault tolerant sensor fusion and how Brooks–Iyengar hybrid algorithm satisfies the requirements of both the inexact-agreement problem and the sensor fusion problem. Additionally, we examine where Brooks–Iyengar algorithm stands in the literature and compare its performance with other distributed agreement algorithms theoretically. Finally, we present a multidimensional sensor fusion algorithm proposed by Brooks and Iyengar and compare its performance with other known methods.