Sketch RR-Tree: A Spatio-Temporal Aggregation Index for Network-Constrained Moving Objects

Traffic aggregate information is important for Intelligent Transportation Systems. There are two issues in obtaining such information, one is how to aggregate traffic data stream efficiently, and another is how to process the "network-constrained" property of the traffic data. This paper solves this problem by proposing an index structure for network-constrained data stream, which manages the sketch synopses of the moving objects in road network considering their "network" positions and supports the effective aggregation on road networks. Evaluation shows the new structure can respond to the aggregate queries on network-constrained data streams within small errors efficiently.