Emuli: Emulated Stimuli for Wireless Sensor Network Experimentation

We describe Emuli — a method of effectively substituting sensor data by synthetic data on physical wireless nodes (motes). The sensor application is oblivious to this substitution. Emuli generates data on demand from the application. The replies are based on the sensor model which is driven by the data pre-loaded to the mote before the experiment. Since the preloaded data is an approximation of the sensor behavior rather than raw sensor readings, it is rather compact. This allows Emuli to drive sophisticated experiments. The emulated stimuli can be synchronized and coordinated across multiple motes which allows to experiment with distributed events. Emuli abstracts the sensing component of a complete application and allows the experimenter to focus only on processing and transport function of a wireless sensor networks. We demonstrate statistical and deterministic sensor models. We showcase the use of Emuli in a light measurement and a target tracking experiment.