=Paper=
{{Paper
|id=Vol-275/paper-25
|storemode=property
|title=Applying Semantic Technologies to the Design of Open Serivce-oriented Architectures for Geospatial Applications
|pdfUrl=https://ceur-ws.org/Vol-275/paper25.pdf
|volume=Vol-275
|dblpUrl=https://dblp.org/rec/conf/esws/Uslander07
}}
==Applying Semantic Technologies to the Design of Open Serivce-oriented Architectures for Geospatial Applications==
<pdf width="1500px">https://ceur-ws.org/Vol-275/paper25.pdf</pdf>
<pre>
        Applying Semantic Technologies to the Design of
          Open Service-oriented Architectures for
                  Geospatial Applications

                                     Thomas Usländer

                    Fraunhofer IITB, Fraunhoferstr. 1, D-76131 Karlsruhe
                           thomas.uslaender@iitb.fraunhofer.de



1    Research Problem

   Up to now, there is no established methodology for the design of a geospatial ser-
vice-oriented architecture (SOA), e.g., for environmental risk management applica-
tions. However, there are key design guidelines and constraints imposed by corre-
sponding standards of ISO and the Open Geospatial Consortium (OGC). Standards
exist on both the abstract (i.e. platform-neutral) and the concrete (i.e. platform-
specific) level, e.g. Web services, but still focus on syntactic interoperability.
   An example motivates the application of semantics: As part of a forest fire risk as-
sessment process in Spain the need to access to “vulnerable infrastructure in Catalo-
nia” has been identified. The abstract service platform offers the capability of a ge-
neric feature (object) access service that supports queries with geospatial filters.
Currently, it is up to the SOA designer to establish a conceptual connection between
“infrastructure in Catalonia” and “features”. An ontological approach that knows the
subsumption chain (“road” is-a “infrastructure element” is-a “feature”) and knows
that “Catalonia” is a geographical concept would help in the “early service discovery”
and would open up new perspectives for (semi-)automated service engineering.




                      Fig. 1: Mapping of requirements to capabilities

   A generic solution to such a design problem leads to the scientific kernel problem
of semantically matching requirements of one abstraction layer A to capabilities of
another abstraction layer B (see Fig. 1), taking side conditions explicitly into account.
This kernel problem iteratively occurs when user requirements are broken down to




                                            -1-
capabilities of the next level. The task of mediation as a generic mechanism to bridge
the gap between heterogeneous descriptions and/or expectations [2] plays a key role.
   The thesis proposes a semantic SOA modelling framework (MFgeo) as a solution.


2    Methodology

   Five different ontology types are proposed in [1] that contribute to forming a geo-
spatial system. With MFgeo the thesis proposes a complementary, geospatial SOA
design ontology as missing link for the design phase targeted at analysts and archi-
tects of geospatial applications. Emerging semantic web services frameworks such as
WSMO, OWL-S or WSDL-S form the baseline of the methodology and will be con-
sidered in the context of existing geospatial ISO/OGC standards. MFgeo will support
1. annotation of informational, functional and qualitative requirements and discovery
   of capabilities triggered by domain, service and quality of service ontologies,
2. an iterative design process with a flexible mediation technique of requirements and
   capabilities taking side constraints, e.g. compliance to OGC standards and re-use of
   existing information and service models, explicitly into account,
3. means to document the design process enabling traceability of the user require-
   ments and validation using reasoning tools, and
4. the specification of policies to monitor and control the operation of deployed ser-
   vice networks.


3    Current Results and Planning

   Result so far is the architecture specification of the European Integrated Project
ORCHESTRA [3] accepted as OGC discussion paper that has extended the OGC Ref-
erence Model by 1) a common meta-model approach for the service and information
viewpoint, 2) the modelling of the mapping from the abstract to the concrete service
platform, 3) a meta-information schema enabling semantic descriptions of geospatial
resources, and 4) the consideration of policies in the engineering step of service net-
works. The current work focuses on semantic extensions of [3] followed by the design
of MFgeo in 2008. The approach will be assessed by using MFgeo for an alternate on-
tology-driven design of an existing ORCHESTRA pilot application.


References

1. Rodriguez M.A., Cruz, I.F., Egenhofer, M.J. and Levashkin, S. (Eds.). GeoSpatial Seman-
   tics. First International Conference GeoS, Mexico City, 2005, LNCS 3799, 2005.
2. OASIS Semantic Execution Environment TC. Reference Model for Semantic Service Ori-
   ented Architecture. Working Draft 0.1, 2006, http://www.oasis-open.org.
3. Usländer, T. (Ed.). Reference Model for the ORCHESTRA Architecture (RM-OA) V2 (Rev
   2.0). OGC 07-024, http://www.eu-orchestra.org/publications.shtml#OAspecs, 2007.




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