Indexing And Querying Of Moving Objects In Road Network Based Moving Objects Database

Moving Objects Database (MOD) is a database which can manage the moving objects (such as vehicles, airplanes and moving users) and their positions. In real world, many moving objects are constraint to a certain topology network called the road network. Traditional database technology is not able to manage this kind of moving object. Road network based moving objects database could be used in several application domains, such as airplane control system, traffic control system and LBS (Location Based Service).In the part of indexing the road network, we proposed an indexing mechanism named RNT (Road Network Tree). RNT divides the road network into many polygons in terms of its constitution. Because it can avoid the overlap of polygons, the query path is exclusive. RNT could position the moving object to the road segment it belongs to quickly from its spatial coordinate.In the part of indexing the moving objects based on the road network, we proposed an indexing mechanism named RMHASH. In terms of the characteristics of moving objects on road, RMHASH employed a dynamic splitting way of the bucket and put moving objects into different buckets. RMHASH solved the problem of heavy load of the database system made by the great number of moving objects and its high frequent position update.The part of query based on road network includes position moving objects, road segment status query, range query and optimal route query.