Data Validity and Dependable Perception in Networked Sensor-Based Systems

Although the technology and applications of wireless sensor networks have greatly increased over the last years, ensuring a dependable real-time operation despite faults and temporal uncertainties is still an on-going research topic. The problems are particularly significant when considering that future applications will interact with their environment not only for supervision or monitoring, but also to directly control physical (real-time) entities, sometimes with safety-critical requirements. We believe that reasoning in terms of data validity might be a good way to approach the problem. The ability to know if sensor data flowing in the system is valid - data validity awareness -, is a first step to achieve a dependable operation. But more than that, it should be possible to ensure, given requirements for data validity throughout the operation, a dependable perception of the environment. In this paper we essentially discuss the problem, analyzing some of the issues that need to be addressed to achieve these goals. Particularly, we introduce fundamental concepts and relevant definitions, we elaborate on the main impediments to achieve data validity awareness and describe relevant means to deal with these impediments. Finally, we address the issue of ensuring a dependable perception and present some research ideas in this direction.