A Web-based Distributed A Web-based Distributed Simulation SystemSimulation System
Christopher Taewan Ryu
Computer Science Department
California State University, Fullerton
OverviewOverview
Project backgroundHLAA web-based distributed simulation Implementation approachFuture work
Project BackgroundProject Background
Telecommunication Forecaster Predictor (TFP)– Performs analysis on communications between DSN sites and
spacecrafts
Web-TFP (Web version of TFP)
– No program installation or upgrade– No data updating and reconfiguration– No license– TFP anywhere and anytime with a browser
Linux or Solaris Server
Architecture of Web-TFPArchitecture of Web-TFP
ClientApache
PHP/JAVA
Matlab
MatlabCGI or DWR
MatlabServer TFP
WebBrowser
5
Input Parameters, data files, and program
files Operation Select a mission Interface Run
Receive output
Computer SimulationComputer Simulation
Importance of Computer Simulation– For significant cost saving, better control and understanding of
given objects and phenomenon Defense, medical, entertainment, etc.
– Important in building many mission-critical systems such as space mission and defense applications--high cost and reliability.
Challenges– Developing a realistic complex simulation system requires
tremendous amount of time and effort– Many simulation systems in different organizations (e.g., DoD,
NASA have developed various simulation systems in the past).– Interoperability among different systems– Reusability
High Level Architecture (HLA)High Level Architecture (HLA)
First developed by the DoD– To support interoperability and reuse
HLA has been standardized for distributed computer simulations under IEEE Standard 1516.– Any system that conform to the standard can work with any HLA
implementation based on the same standard
Several open-source implementations of HLA such as Open HLA (OHLA) and Portico are available (in Java, C++). – Portico fully conform to IEEE Standard 1516.
HLA FrameworkHLA Framework
RTI is the fundamental component of HLA– Provides a set of software services that are necessary to support federates to
coordinate their operations and data exchange during a runtime execution.
Simulations don’t communicate with each other directly. All communications among simulations are managed by RTI
– providing high scalability, interoperability, and reusability of components.
…
ArchitectureArchitecture
Proxy federate is to support Web service (implementation of SOA) Web service and HLA provides different levels of interoperability
– Scalability and performance
HLAGUI (Java Web Start)
Simulation Monitor (Java 3D)
Simulation Monitor (Java 3D)
Web ServiceWeb
Service
RTIRTI
Simulation ControllerSimulation Controller
FederateFederate
Proxy Federate
Proxy Federate
Environment SetupEnvironment Setup
Portico for RTI– Can run on Windows, Linux, or Mac platforms.
Apache TomcatApache AxisJava 3D
Target simulations, Internet, Browser
Advantages and Disadvantages of Advantages and Disadvantages of Web Services in HLAWeb Services in HLA
Advantages– Substantially larger set of development environment and
languages (that can be supported by HLA)– Easier to deploy HLA federates in WAN environment using
HTTP protocol (stateless)– Larger scale of interoperability– Can you web browser as interface (all advantages of web
browser)—particularly important to our project
Disadvantages– Lower performance than C++ or Java API– May require additional knowledge on Web service and HTTP
Future WorkFuture Work
Migrate the Web-TFP or other related systems to the HLA-based platform
Provide 3D interfaces for users for better interaction