14.1 Introduction

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Human exploration and development of space will involve opening the space frontier by exploring, using, and enabling the development of space through information technology, while expanding the human experience into the far reaches of space. At that point in time we assert that the current primitive World Wide Web (Web) will be replaced and dramatically expanded into an interstellar Space Wide Web (SWW). The current state-of-the-art low-orbit communications satellites constellations will be dramatically expanded to higher orbits and to orbits supporting work on remote human colonies. This will be necessary in order to furnish in a human-friendly way the necessary software and information that will be needed in support of interstellar spacewide information technologies. Many of the problems encountered in conceiving of, modeling, designing, and deploying such a facility will be different from those problems encountered in today's Web. Future research and development work will be to identify some of these problems and to conceptually model a few of their solutions. In this work we describe research into the development of scalable tools and techniques that reduce the effort associated with component integration, both with respect to network environments and with respect to other components within the application. Our approach is also targeted at increasing the reusability of software components and software architectures. Our research is to investigate current problems in leveraging adapters as a means to configure large-scale next-generation distributed systems software from reusable architectures and components. Our approach to solving this problem is through the development of a novel configuration model and network-aware runtime environment called SWWACXML, an abbreviation for Space Wide Web Adapter Configuration eXtensible Markup Language. SWWACXML provides support for cross-layer architectural configuration at both the application level and the level of individual network connections. The language associated with this environment captures component interaction properties and network-level QoS constraints. Adapters will be generated automatically from SWWACXML specifications. These adapters are part of the SWWACXML runtime system. The runtime system includes facilities for automatic configuration and runtime reconfiguration, as well as efficient management of network connections and QoS options. This facilitates reuse because components are not tied to interactions or environments. Another aspect of this work will focus on development and experimentation with a novel Web-based interaction paradigm that allows client adapters to tailor themselves to servers at runtime. One of the strengths of our approach is that clients do not have to be tied to specific servers at implementation time. Rather, a client's adapter loads an SWWACXML configuration page from the server. The SWWACXML configuration page defines the appropriate interaction, including management of heterogeneous network QoS options. We believe our approach is amenable to facilitate a style of dynamic reconfiguration, where clients can at runtime change server, communication, or interaction protocol. Future researchers and developers will design and implement the SWWACXML system in a distributed test bed. They will develop performance analysis techniques to judge the success and efficiency of our approach.


Part IV: Applications of XML