NodeMD: diagnosing node-level faults in remote wireless sensor systems

Software failures in wireless sensor systems are notoriously difficult to debug. Resource constraints in wireless deployments substantially restrict visibility into the root causes of node-level system and application faults. At the same time, the high cost of deployment ofwireless sensor systems often far exceeds the cumulative cost of allother sensor hardware, so that software failures that completely disable a node are prohibitively expensive to repair in real worldapplications, e.g. by on-site visits to replace or reset nodes. We describe NodeMD, a deployment management system that successfully implements lightweight run-time detection, logging, and notificationof software faults on wireless mote-class devices. NodeMD introduces a debug mode that catches a failure before it completely disables a node and drops the node into a stable state that enables further diagnosis and correction, thus avoiding on-site redeployment. We analyze the performance of NodeMD on a real world application ofwireless sensor systems.