Context-aware System Based On The Upnp Service Discovery And Management,

In respect of various services in context-aware computing applications, service discovery has been drawing much attention from researchers. The existing service discovery systems, like SLP, Jini, UPnP, Salutation, and so on, provide basic infrastructures where services can announce their presence and users can locate services across the network. However, several issues are not completely solved such as scalability, dynamics and so on. Concerning this, a design for service discovery based on UPnP in context-aware computing applications is proposed, and the context-aware applications are disposed on the platform of OSGi.Firstly, the paper introduces the main technologies used to implement the context-aware infrastructure and the service discovery sub-system, such as the origin of context-aware computing, the Semantic Web, the Ontology and so on.Secondly, the paper presents several basic concepts and characteristics of OSGi, and then puts forward a new context-aware infrastructure which is dispatchable, and introduces the components and programming abstractions in detail.Thirdly, the paper tells the basic principle and several important concepts of UPnP, and then the paper compares several existing service discovery systems such as SLP, Jini, UPnP and Salutation, and analyzes the differences in their realization and applicability between them. Then, the paper designs the service discovery sub-system and implements the service discovery sub-system in Java. The component-based infrastructure makes it easier to provide service registration, service discovery and event transfer for applications.Fourthly, an X-10 light device based on UPnP is implemented, and then the description file and the interface is introduced in detail.The case study, validates our work, and illustrates, in concrete form, the process and issues involved in the design of context-aware software.Finally, some improvements of UPnP based service discovery sub-system are summarized.