Efficient XML Interchange (EXI) compression and performance benefits : development, implementation and evaluation

Abstract

The Department of Defense (DoD) Network-Centric data sharing strategy for the Global Information Grid (GIG) is to XMLize all data. The goal of this strategy is to ensure all data is visible, usable and interoperable, when and where needed, to accelerate decision cycles. However, this XML-based data approach comes at the cost of limiting real-time network edge device connectivity to the GIG because they are seldom able to meet the necessary bandwidth and processing requirements due to XML's intrinsic nature of being verbose and often complex to process. This research explores a powerful and robust solution to XML's network depth limits by means of the World Wide Web Consortium's (W3C) proposed alternative XML format, Efficient XML Interchange (EXI). The EXI format removes redundant tags and values from XML documents and encodes numeric content in a binary format. This format delivers significant file size savings and processing efficiencies compared to existing practices. The evolution of XML's path to EXI is summarized based on the results of the XML Binary Characterization (XBC) working group and the W3C's design points of XML. Followed are recommended steps for EXI development and enterprise integration, focusing on a public open source licensing philosophy. EXI algorithms are described with detailed explanations, Java code samples, and part-task test XML documents. Experiments are conducted evaluating the effectiveness of EXI for DoD tactical use and is followed with a recommended optimal EXI configuration. Several predictive models of EXI's performance are presented to enable potential EXI adopters a measurement tool of expected EXI benefit for various XML domains. This research concludes that for XML-based data, a doubling of bandwidth potential is achievable and CPU burdens minimized when EXI is applied. Additional findings indicate that traditional binary data formats converted to an XML format can be smaller than their native binary format after the application of EXI. Ultimately, through EXI, DoD network edge devices can join the GIG in real-time data exchanges without network hardware refactoring, delivering a more able force.