Research On Web Services Composition Based On QoS In Internet Of Things

The Internet of Things is a new technology that composed of embedded, computing and networking technology. Its emergence has changed the way to get resources and information, also changed the way to spread information. Integrating various services, and providing personalized service that adapt to changes of environment for business or user regardless of when and where, is the key to successful application of the Internet of Things. The Internet of Things has characteristics of heterogeneous environment and dynamic resources, in this network environment, to develop and integrate information, adopting services-oriented approach is widely accepted and has been widely applied. Therefore, the combination of Service-Oriented Architecture and Internet of Things become a hot research topic.At present, domestic and foreign scholars has done a lot of work in integration of the physical world and the enterprise application, and proposed that the Web services standards are applied directly on the physical objects, each physical object provide its functionality as standard services. This will bring some new problems, because these services are different from the traditional services, and their environment is dynamic, the Web services standards is not appropriate to apply on them directly. This means that we need change the way of the service description and services composition. Based on the research background and analysis of current problems, this article will be research of the service composition in the Internet of Things.In this paper, we do a detailed analysis and research on the services for the Internet of Things, analyze the differences between traditional services and the services that real-world devices provide. Aim at the dynamic computing environment for the Internet of Things, in order to provide appropriate service for user, service Composition can not only satisfy the needs of users, but also adapt to dynamic environment, this different from the traditional service composition. We propose a context-based service composition approach. At the same time, more and more services that the heterogeneous devices provide with privacy and valuable information are exposed on the network, which will bring a serious threat to existing security systems. Unlike traditional services, these services are limited to their physical location and influenced by the surrounding environment. Aim at the features of the services for the Internet of things, this paper proposes an extended role-based access control model. In our model, the context information is used for the design of access control mechanisms. Through the constraints of the context information, we have improved the flexibility of access control, and finally proved its feasibility and safety by an example.