MV-3500

MV-3500
DoD Modeling & Simulation Network
Protocols
Admin
This class is intended to introduce you to the
simulation network protocols used in DoD
M&S applications
This will require a little background on
networking first, then we can look at two of
the major protocols, DIS and HLA. As time
permits we will look at some others: TENA
(range operations) and emerging web
standards
Admin
Grading
• Two midterms (50%)
• Final project (25%)
• Programming assignments (25%)
Contact:
Watkins 281 (stop by any time)
Phone (don’t) x-7605
Email:mcgredo at nps edu; put MV3500 in the subject
Web page:
https://www.movesinstitute.org/~mcgredo/mv3500
Textbook
Networked Graphics, Steed & Oliveira
Read chapters 1 & 2
Chapter 2 will probably be over your head a bit;
just go with it.
Other Sources
“I want to know everything about networking”
Stevens: Unix Network Programming, TCP/IP Illustrated
(V 1, 2, 3)
Zyda: Networked Virtual Environments
Gaffer on Games: http://gafferongames.com/
Game Developer’s Conference
Some techniques are encumbered with Intellectual
Property restrictions
Neyland: Virtual Combat: A Guide to DIS
SISO: DIS Plain and Simple
Background
What do network protocols do?
Basically, they are an agreed-upon way for
simulations to talk to each other
If you have a Boeing flight simulator and a
General Dynamics tank simulator and a
Hughes helicopter trainer, it would be helpful
if all of them could cooperate in the same
virtual environment
Virtual World
GD Tank
Simulator
Sikorsky Helo
Simulator
“Virtual World?”
Huh? What’s a virtual world or a “Networked Virtual
Environment?”
An illusion of a virtual environment that is shared
between participating users. This is typically done
across a network. In the tanks & helos example, we
have a virtual battlefield, users controlling vehicles,
and each user can view the virtual world from their
own point of view.
Military M&S can encompass much more than NVEs, for
example analytic simulations.
Live, Virtual, Constructive
Live Simulation: Real people using simulated
equipment. Example: marksmanship simulators,
some tank simulators
Virtual Simulation: Real people use simulated
equipment in a virtual world
Constructive: Simulated people using simulated
equipment in a simulated environment
We can mix & match these to an extent. For example,
live elements to a virtual simulation, a virtual
simulation with constructive participants, etc.
Applications
Massively Multiplayer Online Games (MMOG), sort of
the commercial application of military R&D over the
last 20 years. Large scale, with thousands or tens of
thousands of participants
Online worlds--live simulations and role playing in a
virtual world; less emphasis on physics, more on
human interaction. Second Life, Open Simulator
To an extent there has been a convergence between
the capabilities of military & commercial, but
commercial is heavily focused on games
Military Simulations
JANUS
OneSAF
ModSAF
Lots and lots more. Many of these use DIS or
HLA as a way to connect simulations
Protocols
So how do simulations talk to each other?
Generally this happens across the network
(“distributed”) as multiple computers cooperate on
the problem.
The substrate used by all modern simulations is TCP/IP
sockets
Started with ad-hoc protocols, made up for each task
Moved on to Distributed Interactive Simulation (DIS)
and High Level Architecture (HLA)
Web Services (XML based) are emerging
Protocols
Application/Simulation
Ad-Hoc
Protocols
DIS
HLA
TCP/IP Sockets
Web
Services
Background
During this class, we’ll look at each of these
elements:
• TCP/IP sockets
• Ad-hoc protocols
• DIS
• HLA
• Web Services