Workflow-Oriented the optimal path web services in multi-level road network

Usually, a typical city road network is very huge, including thousands upon thousands of nodes. If several cities are considered, even countrywide or larger area, the classical algorithm is very difficult to get a correct result. To solve this problem effectively, when a mass of data is given, distributed multi-level road network data is considered. It builds pyramid-liked data model, calculates the optimal path analysis in multiple layers, and then conflates the final results by sub-result coming from multi-levels. With development of Web service technology and Internet network, it provided necessary preparation for data sharing and interoperability of distributed information. So it provides technique support for a dynamical building of pyramid-liked multi-level road network data model and an optimal path service. Workflow technology can effectively build all data sharing Web services and functional Web services into one executable service chain. Using self-developed workflow software will combine related Web services into an abstract service chain. The abstract service chain is mapped into BPEL standards service chain. Finally, the Active BPEL workflow engine will be used to implement the service chain, and the results will be sent to the client. The service application proves that the optimal path service on multi-level road network is feasible and efficient to deal with large area optimal path analysis problem.