MEDAL: A compact event description and analysis language for wireless sensor networks

Event detection plays an important role in wireless sensor network (WSN) applications such as battlefield surveillance and habitat monitoring. However, effective approaches for specifying events in a sensor network remain a challenge. In this paper we present MEDAL, a formal event description language. MEDAL is a modified Petri net which provides a more compact formal language than its predecessor SNEDL. As a system analysis tool, MEDAL can capture the structural, spatial, and temporal properties of a complex event detection system, which can be used to assist system designers in identifying inconsistencies and potential problems. MEDAL can also perform case-specific analyses that can make the debugging phase easier. We present a case study as an example illustrating the features and effectiveness of MEDAL. We also describe an approach for simultaneous detection of multiple events in a single WSN.