Location-based Spatial Queries with Data Sharing in Mobile Environments

Mobile clients feature increasingly sophisticated wireless networking support that enables real-time information exchange with remote databases. Location-dependent spatial queries, such as determining the proximity of stationary objects (e.g., restaurants and gas stations) are an important class of inquiries. We present novel approaches to support nearest-neighbor queries and window queries from mobile hosts by leveraging the sharing capabilities of wireless ad-hoc networks. We illustrate how previous query results cached in the local storage of neighboring mobile peers can be leveraged to either fully or partially compute and verify spatial queries at a local host. The feasibility and appeal of our technique is illustrated through extensive simulation results that indicate a considerable reduction of the query load on the remote database. Furthermore, the scalability of our approaches is excellent because a higher density of mobile hosts increases its effectiveness.