Debugging Wireless Sensor Networks Using Mobile Actors

Large-scale deployments of sensor networks can potentially serve as infrastructure for multiple, concurrent applications. Realizing this potential requires tools for monitoring, debugging and repairing deployed wireless sensor networks (WSNs). We propose an approach for post-mortem debugging of WSNs using autonomous and mobile actors. By allowing the computation (mobile actor) to move to the nodes where the data is located, we overcome the necessity of moving the data while still providing the flexibility necessary to diagnose errors in WSNs. We define two mechanisms for debugging–namely, forward tracking and backward tracking in which an actor, starting at an error state, tracks the causal events, respectively, forward or backward in time in order to determine the root cause of the error. We show that mobile actors enable both forward and backward tracking, and these may be useful under different conditions.