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

6

7

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.

…

USE Case Diagram for Our ProjectUSE Case Diagram for Our Project

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

Deployment EnvironmentDeployment Environment

Environment SetupEnvironment Setup

Portico for RTI– Can run on Windows, Linux, or Mac platforms.

Apache TomcatApache AxisJava 3D

Target simulations, Internet, Browser

Detailed DeploymentDetailed Deployment

InterfacesInterfaces

Simulation objects are be added using the console

Simulation in OperationSimulation in Operation

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

Thank you.Thank you.