Processing Approximate Moving Range Queries in Mobile Sensor Environments

The ubiquity of mobile devices has led to a rising demand for location-based services and applications. A major part of these services is based on the location-detection capabilities of the mobile devices. Utilization of location data reported by the devices is associated with a certain amount of uncertainty due to the devicepsilas mobility. In this paper, we examine an environment, which consists of mobile objects with no location-detection capabilities, and location-aware mobile sensors randomly scattered, that can sense the presence of mobile devices. These sensors can detect the identities of mobile objects that come within their sensing ranges but cannot infer their exact locations. The sensor readings are periodically reported to a database server. This system supports processing of mobile location-dependent range queries over mobile objects. The answer set of each query carries a certain degree of uncertainty due to the approximate nature of the reported object location data. We exploit scenarios of sensor range overlap to reduce the uncertainty inherent in the query result. Our work is validated through an extensive simulation study that provides assessment of the query results accuracy.