The tree-based languages XQuery and XSLT for XML are widely supported. Many tools do not yet support the new RDF graph query language SPARQL. We propose to embed SPARQL subqueries into XQuery/XSLT, such that XQuery and XSLT benefit from the graph query language constructs of SPARQL, and SPARQL benefits from features of XQuery/XSLT, which SPARQL does not support. The embedding enables XQuery/XSLT tools to handle at the same time XML queries and SPARQL subqueries, and XML and RDF data.

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Continuous Queries (CQ) can be used to keep track of relevant information in the WorldWide Web and Sensor Networks over a period of time. However, result sets may become unbounded and notifications can be delayed. A special form of CQ are Bounded Continuous Search Queries (BCSQ), where results are processed immediately and a bounding condition for the number of user notifications may be defined to limit the result set. Based on a theoretical background for answering BCSQ we present smartCQ, a web application for processing BCSQ and evaluating the query results. Based on a transparent search engine a user may execute and evaluate new strategies and methods for continuous search queries. Furthermore because of the positive results of BCSQ we encourage its use for querying Wireless Sensor Networks to reduce the communication demand and hence reduce the energy consumption to enhance the lifetime of a sensor network.

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Integrating wireless sensor networks in heterogeneous networks is a complex task. A reason is the absence of a standardized data exchange format that is supported in all participating sub networks. XML has evolved to the de facto standard data exchange format between heterogeneous networks and systems. However, XML usage within sensor networks has not been introduced because of the limited hardware resources. In this paper, we introduce XML template objects making XML usage applicable within sensor networks. This new XML data binding technique provides significant high compression results while still allowing dynamic XML processing and XML navigation. This is a step towards more complex but exchangeable data management in sensor networks and the extension of the service-oriented paradigm to sensor network application engineering.

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Despite much research in the area of wireless sensor networks in recent years, the programming of sensor nodes is still time-consuming and tedious. A new paradigm which seems to be qualified to simplify the programming of sensor networks is the Service Oriented Architecture. The composition of simple services to more complex ones can be a convenient way to design applications. To enable the sophisticated techniques known from service oriented architectures like replication and migration of services, a transaction model for sensor networks is required. In this paper, we study the applicability of the standard commit protocols Two Phase Commit (2PC) and Transaction Commit On Timeout and show in experiments with real sensor nodes that 2PC can enable consistent service migration in wireless sensor networks.