An interface-based naming system for ubiquitous internet applications

In the future, huge amounts of embedded and invisible devices, as well as software components, will be connected to the Internet, and these "functional objects" are expected to play an important role in providing convenience services to users. In such a "ubiquitous Internet," users will be able to utilize various applications through functional objects anytime and anywhere. Since the ubiquitous Internet will be a highly dynamic, heterogeneous, and context-dependent environment, applications should be able to change their functionality depending on dynamically changing user context. For example, when a user wishes to brows a PDF file on his small PDA display, a document-browsing application running on the PDA will need an additional transcoder function to reformat the PDF file. If the user wishes to use a voice-only device, such as a PDC (Personal Digital Cellular), to obtain information in the PDF document, the application will need to locate and use a PDF-to-text function as well as a text-to-voice function. Thus, to enable ubiquitous Internet applications to change their functionality on the fly, a mechanism capable of locating the appropriate functions transparently on the Internet is necessary. Generally, such locating mechanisms can be supported by a location-independent naming system. However, the name space of such a naming system tends to be flat; therefore, designing a scalable naming system is quite challenging. This paper describes the design of a new scalable location-independent naming system, called Interface-based Naming System (IFNS), which is capable of locating functional objects transparently in a ubiquitous Internet. In the design of IFNS, we utilize interface information to name functional objects. Interface information enables us to design scalable name management and name resolution algorithms in a fully distributed manner. In addition, interface information not only enables the transparent location of functional objects, but also enables the naming system to support automatic function synthesis. Simulation results show that the proposed IFNS has acceptable scalability and performance for utilizing functional objects in a ubiquitous Internet environment.