DMSO Technical Exchange 3 Oct 03 1 Web Services Supporting Simulation to Global Information Grid...
-
Upload
meryl-hines -
Category
Documents
-
view
215 -
download
0
Transcript of DMSO Technical Exchange 3 Oct 03 1 Web Services Supporting Simulation to Global Information Grid...
DMSO Technical Exchange 3 Oct 03 1
Web Services SupportingSimulation to Global Information Grid
Mark Pullen
George Mason Universitywith support from partners
Don Brutzman, NPS
Andreas Tolk, ODU
Katherine Morse, SAIC
DMSO Technical Exchange 3 Oct 03 2
Extensible Modeling & Simulation Reporthttp://www.movesinstitute.org/xmsf
Web-based technologies applied within an extensible framework will enable a new generation of modeling & simulation (M&S) applications to emerge, develop and interoperate.
Support for operational tactical systems is a missing but essential requirement for such M&S applications frameworks.
The framework of Extensible Markup Language (XML)-based languages can provide a bridge between forthcoming M&S requirements and open/commercial web standards, while continuing to support existing M&S technologies.
Compatible and complementary technical approaches are now possible for model definition, simulation execution, network-based education, network scalability, and 2D/3D graphics views.
The Web approach for technology, software tools, content production and broad use provides best business cases from an enterprise-wide (i.e. world wide) perspective.
DMSO Technical Exchange 3 Oct 03 3
Web Services
• Definition: a self-contained, self-describing unit of modularity for publishing and delivering XML-based digital services over the Internet.
• natural extension of the concept of a resource– sits on the network and does something we need
• accepts messages and returns replies– encoded in XML– peer-to-peer or client-server
DMSO Technical Exchange 3 Oct 03 4
Specifying Web Services
• Externally visible behavior is described in terms of the syntax, semantics, and sequencing of messages exchanged between the service provider and its client
• Described using an XML Schema vocabulary• Web Service interface description document
specifies a contract between the service provider and its client.
DMSO Technical Exchange 3 Oct 03 5
Web Services Model
ServiceProvider
ServiceConsumer
ServiceRegistry
DMSO Technical Exchange 3 Oct 03 6
XML
• Universal meta-language of the Web • Used for data, content, messaging, and
computing to provide point-to-point integration in a platform-neutral way
• Document structure, content and semantics defined by XML schema
• Basis for a new generation of lightweight application-level protocols now emerging
DMSO Technical Exchange 3 Oct 03 7
Simple Object Access Protocol(SOAP)
• XML-based, lightweight messaging protocol for exchange of typed information in decentralized, distributed environments
• Enables interoperability among (existing) distributed applications running on disparate, heterogeneous platforms using a modest infrastructure
• Guiding principles are simplicity and extensibility by modularity.
• Does not define a programming model or require a specific network transport.
• Simply consists of a modular packaging mechanism and a set of encoding rules.
DMSO Technical Exchange 3 Oct 03 8
Implementing Web Services
• Develop an ontology for data management– use it to define an XML tagset
• Define the services to be provided– any function is a candidate– an example: digital terrain
• Provide software for each service– new development: generally in Java– legacy code easily wrapped to appear as a service
• Package the XML in SOAP for transmission• Interoperate!
– examples: XDV via Web-Enabled RTI; XBML
DMSO Technical Exchange 3 Oct 03 9
Critical Points
• XML is a mature technical standard for information exchange– and getting even better: compressed/binary form soon– but it is useless without data management namespace
• SOAP is an effective means to transport XML-encoded data across networks– but it is only a component of a larger system
• There is no magic here, just better technology– software is still complex and expensive!– but interoperation is simpler to achieve– and technology development paid for commercially
DMSO Technical Exchange 3 Oct 03 10
How Does This Relate to the GIG?
• XML/SOAP are great for data distribution– support the Common Operating Picture
• But to get to the next level up, we still need to deal with meta-information– behavioral representation composability, as in XBML
• The simulation community has begun work on Web Service Profiles to support this
• The same technologies empower the GIG– we need to manage the namespaces and meta-
information so they work together– then M&S becomes a powerful C4I system capability
DMSO Technical Exchange 3 Oct 03 11
One View of the Future
Comms
Backbone
Edge Users
GIGEnterpriseServices
NetCentric
Enterprise Services
MessagingESM
Discovery Collaboration
Mediation Security
AppStorage
Notional only - does not imply one “box” per service etc.
Etc.
UserAsst
M&S Service
M&S Service
M&S Service
Communities of Interest