Window Query Processing in Highly Dynamic Geo-Sensor Networks: Issues and Solutions
Yingqi Xu, Wang-Chien Lee · 2003
Wireless sensor networks have recently received a lot of attention due to a wide range of applications such as object tracking, environmental monitoring, warehouse inventory, and health care [15, 29]. In these applications, physical data is continuously collected by the sensor nodes in order to facilitate application specific processing and analysis. A database-style query interface is natural for development of applications and systems on sensor networks. There are projects pursuing this research direction [13, 14, 25]. However, these existing works have not yet explored the spatial property and the dynamic characteristics of sensor networks. In this paper, we investigate how to process a window query in highly dynamic GeoSensor networks and propose several innovative ideas on enabling techniques. The networks considered are highly dynamic because the sensor nodes can move around (by self-propelling or attaching themselves to moving objects) as well as turn to sleeping mode. There exist many research issues in executing a window query in such sensor networks. The dynamic characteristics make those issues non-trivial. A critical set of networking protocols and access methods need to be developed. In this paper, we present a location-based stateless protocol for routing a window query to its targeted area, a space-dividing algorithm for query propagation and data aggregation in the queried area, and a solution to address the user mobility issue when the query result is returned. 1.