Stream-Based XML Template Compression for Wireless Sensor Network Data Management

Abstract

Using structured data formats like XML in wireless sensor networks to support exchangeability and heterogeneity on application level has become an important research topic in the area of large scale networked sensing systems. Besides, the usage of XML encourages the adaptation of service oriented programming techniques to simplify sensor network application engineering. While the sensor nodes still have significant resource limitations in terms of energy and memory capacity and computational power, recent data management approaches show positive results to bridge this resource gap. Nevertheless, further optimizations are needed to enhance the application range to support larger sets of data within the networks. In this work we present an optimization for a template object compression scheme that is based on a stream-oriented XML compression and supports dynamic data management and query evaluation on the compressed data. We hereby present a complete solution for XML compression, data processing and query evaluation that can be further embedded in the engineering process to support developers. The presented solutions are evaluated and result into significant improvements in comparison to previous approaches, when processing complex large scale XML documents.

Eliminating the XML overhead in embedded XML languages

“…A further advantage of the XOBE SN precompiler is the compression of embedded XML data, which we explain in the following paragraphs. This paper extends the contributions of [16][17] by reformulating queries according to the compressed datastructure of the embedded XML data, such that the query is much faster evaluated by a more direct navigation to its result. The query reformulation and evaluation is explained in more detail in the next chapter.…”

“…No contribution to embedded languages discusses compression techniques except those for XOBE [16][17]. [17] is an embedded language for XML data and queries.…”

“…Originally designed to detect type errors already at compile time, XOBE has been ported to the domain of sensor networks, which is named XOBE SN and has additional goals to overcome limitations of restrictive resources. Due to the usage of sophisticated compression techniques [16][17] of the embedded XML data, it is possible to use XML even on devices with restrictive space like sensor nodes.…”

Context- and Template-Based Compression for Efficient Management of Data Models in Resource-Constrained Systems

“…Hoeller et al [15,16,17] identified the inefficient management of XML formatted data in resource-constrained devices as a barrier to overcome in order to achieve full interoperability. They defined a series of mechanisms to efficiently manage XML in terms of processing, storing and transmission.…”

XML-compression techniques for efficient network management

“…Sensor node hardware restictions have been addressed using an XPath engine on updateable compressed XML data, reducing memory and energy consumption [24]. Furthermore, this work has been extended to support larger sets of data within the sensor network using stream-oriented XML compression in order to have a dynamic queriable system [25]. This research is motivated by the necessity to improve network management over a wireless embedded internet, however, it can be extended to general networks.…”