Temporal Message Ordering in Wireless Sensor Networks

Wireless sensor networks (WSN) are envisioned to fulfill complex monitoring tasks in the near future. A typical WSN application like object tracking fuses sensor readings produced by nodes throughout the network to obtain a high-level sensing result such as the current speed of a tracked vehicle. In order to produce correct results, the application typically has to process sensor events in the order of their occurrence at the sensor nodes. Temporal message ordering ensures that sensor events arrive at the application in this order. Due to the requirements and characteristics of sensor networks, temporal message ordering is a non-trivial problem in this environment. We motivate the need for temporal message ordering in WSN and present an energy efficient temporal message ordering scheme for sensor networks.