OpenGIS
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Engineering Report OGC 11-097
Copyright © 2011 Open Geospatial Consortium. 8
OGC
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OWS-8 AIXM 5.1 Compression Benchmarking
1 Introduction
1.1 Scope
AIXM stands today for the de-facto standard for Aeronautical Information Publication, used by air control service providers from Europe, USA and Australia. With version 5.1,
it reaches a level of maturity allowing the support of Digital NOTAMs, as the first official version of these messages was published this year.
In a near future, AIXM will be carried inside WFS requests but also into notification messages along WS event services. This last channel will be the one dedicated to D-
NOTAMs. As D-NOTAM is aimed at aircrafts pilots, their transmission to the aircraft will use airground data link. Today, datalink communications lack bandwidth and future
datalink will still have a limited capacity.
Uploading D-NOTAM aboard raises the question of the pertinence of using XML voluble message through the narrow datalink channel. The viability of AIXM through datalink
relies on how good a compression can be applied on these messages. If proof can be made compressed AIXM doesn’t weight much more than a handmade binary
representation, AIXM should make its way onboard.
This OGC document presents the results of a compression benchmarking campaign of various algorithms applied on AIXM 5.1 files, with a special focus on D-NOTAM 1.0
and today Datalink capacities.
The compression candidates, and input files made the object of a thorough selection and classification in coordination with the aviation thread of OWS-8 team. AIXM inner
characteristics are studied to put light on the benchmark results and provide explanation on the outcomes.
This OGC document also gives recommendation on how to implement compression on clientserver communication using AIXM.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The Open Geospatial Consortium Inc. shall not be held
responsible for identifying any or all such patent rights.
Copyright © 2011 Open Geospatial Consortium
9 Recipients of this document are requested to submit, with their comments, notification of
any relevant patent claims or other intellectual property rights of which they may be aware that might be infringed by any implementation of the standard set forth in this
document, and to provide supporting documentation.
1.2 Document contributor contact points
