Efficient XML Usage within Wireless Sensor Networks Nils Hoeller, Christoph Reinke, Jana Neumann, Sven Groppe, Daniel Boeckmann, Volker Linnemann Institute of Information Systems Ratzeburger Allee 160 23538 Luebeck, Germany {hoeller, reinke, neumann, groppe, boeckmann, linnemann}@ifis.uni-luebeck.de ABSTRACT Integrating wireless sensor networks in heterogeneous net- works is a complex task. A reason is the absence of a stan- dardized data exchange format that is supported in all par- ticipating sub networks. XML has evolved to the de facto standard data exchange format between heterogeneous net- works and systems. However, XML usage within sensor networks has not been introduced because of the limited hardware resources. In this paper, we introduce XML tem- plate objects making XML usage applicable within sensor networks. This new XML data binding technique provides significant high compression results while still allowing dy- namic 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. Categories and Subject Descriptors C.2.4 [Computer-Communication Networks]: Distributed Systems—Distributed applications, Distributed databases ; H.2.4 [Database Management]: Systems—Distributed Databases, Query Processing General Terms Languages, Management, Design Keywords XML, Wireless Sensor Networks, Database Management, Programming Language 1. INTRODUCTION With the rapidly advancing development in the field of microprocessor technology, which results into smaller and more powerful microprocessors, wireless sensor networks are becoming increasingly important. Wireless sensor networks Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. WICON ’08, November 17-19, 2008, Maui, Hawaii, USA Copyright 2008 ICST 978-963-9799-36-3 $5.00. consist of single sensor nodes that combine regular com- puting devices with different sensors for monitoring envi- ronmental conditions and events. Recently, many sensor network deployments have been reported for different ap- plication fields from geological environment monitoring to ubiquitous computing applications [17, 30, 12]. Neverthe- less, sensor network programming remains a highly complex development task and the integration of sensor networks in heterogeneous networks has only been proposed inchoately. Besides, recent sensor network data management approaches only support very simple data structures, like one table per network [31, 16], while there is a need for more complex data structures like those in existing database systems. Hence, the use of a standardized exchange format is desirable while handling this format during programming should be easy and transparent for the developer. A highly exchangeable and extensible data format is XML, which has become the de facto standard for data exchange over the Web. Different query languages, like XPath [26], XSLT [28] and XQuery [27], have been introduced. Using XML in sensor networks encourages the interchangeability of different types of sen- sors and systems, e.g. making it easy to interconnect a sen- sor network to the WWW. In Figure 1 we show a possible scenario. A sensor network can directly be queried using XML query languages by any client that is able to process XML, while the XML result can be further processed, e.g. in order to present it on a webpage. Figure 1: Sensor Networks <-> WWW Integration Digital Object Identifier: 10.4108/ICST.WICON2008.4787 http://dx.doi.org/10.4108/ICST.WICON2008.4787