Research On Measurement And Verification Ofcomposite Service Reliability Based Reasoningin Pervasive Environment

Pervasive computing is getting more and more spotlights along with the development of computer network, sensor network and mobile technology. In pervasive environment, devices have different type and provide disparate functions while various protocols of networks exist and status of resources change dynamically, which causes the reliability of services varies as the context environment is changed. The measurement, forecast and verification of the service reliability is a main issue.Aiming at the problem, this paper brought forward a rule-based reasoning method to measure, forecast and verify reliability of composite services. According to the characters of pervasive environment, a context model and service reliability measuring model based on ontology technology were established. Services reliability was computed by rule-based reasoning through context awareness, and then a verification method of service reliability referred to the request was proposed. Based on the above method, the design and the realization of the prototype system was discussed in detail. And experiments in the scene also proved that the method is feasible and effective.Compared with the traditional methods, this method in this paper has the following points: Firstly, this paper introduced a service reliability measurement model based on ontology technology and computed the reliability of atomic services and their composite services through rule-based reasoning. Secondly, this paper used two-stage method for service reliability measurement and forecast, which computed the simple service reliability through context awareness and reasoning, and then measured the reliability of composite services according to various of control construct.