Motes Sensor Networks in Dynamic Scenarios: an Experimental Study for Pervasive Applications in Urban Environments

Recent works have shown that using mobile elements (or data MULEs) to collect and carry data from sensor networks to a collection point may have significant advantages over traditional ad hoc sensor networks. Previous papers on the MULE architecture are mainly based on simulation and numerical analysis. In this paper we investigate the performance of the data MULE model and its ability to support sensorbased applications in a real urban environment by means of an experimental analysis. Specifically, we use a testbed based on Berkeley motes, and analyze the impact of several parameters (i.e., MULE's speed, distance between the static node and the MULE, duty cycle) on the contact time and the total amount of data that a static node is able to transfer to the mobile MULE when they happen to get in contact. The results obtained are very promising and show that the MULE architecture is really suitable for a large set of sensor-based applications in urban environments, both in low and high mobility scenarios.