A case for meta-triggers in wireless sensor networks

This work addresses the problem of managing the reactive behavior in Wireless Sensor Networks (WSN). We consider settings in which the occurrence of a particular event, detected in a state that satisfies a given condition, should fire the execution of an action. We observe that in WSN settings, both the event and condition may pertain to some continuous phenomena that are monitored by distinct groups of nodes and, in addition, their respective detection may impose an extra communication overhead, if a correct executional behavior is desired in terms of firing the action. Towards that end, we propose the concept of a meta trigger, which essentially translates a particular request, so that the communication overhead among the entities participating in its processing is minimized. We discuss a proof-of-concept implementation which demonstrates the benefits of the proposed methodology on an actual small-size network, and we present a detailed simulation-based experimental evaluation in large-scale networks. Our experiments indicate that the meta-triggers can yield substantial savings in the energy (and bandwidth) expenditures of the network, while preserving the intended executional correctness.