Enhancing reliability of sensor networks by fine tuning their event observation behavior

Sensor Networks are envisioned to be used in large variety of applications - health care, homeland security etc. - which require high reliability. Due to the fact that the sensors need to be low cost they have only scarce resources leading to a certain level of failures of sensor nodes or sensing devices attached to the nodes. For the applications mentioned reliable and fault tolerant sensor networks are in great demand. Available fault tolerant solutions are mainly customized approaches that revealed several shortcomings. We present an event specification language that allows configuring the level of reliability of a certain sensor network. It explicitly regards heterogeneous sensing capabilities and allows defining complex events as well as tailor made voting schemes. Features for multi-event detection facets and for fine-grained event-related fault tolerance are also part of the language. Our approach significantly enhances service and maintenance features and enables online configuration of sensor networks.