Large scale networked system
simulation using MLDesigner
Horst Salzwedel, MLDesign Technologies, Inc.
2130 Hanover, Palo Alto CA 94303, http://www.mldesigner.com
Why MLDesigner uses Ptolemy Technology
What are large scale networked systems (LSNS)?
Challenges and solutions in designing LSNS
Challenges and solutions in simulating LSNS
Summary
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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The Challenge of Complexity
To cope with complexity, model based design
techniques have been used in aerospace industry
throughout its more than 100 years of development
Each time new technologies have been introduced,
existing models have proved to be insufficient
Major problems have been
not validated specifications
incompatible models between disciplines
insufficient testing against specifications
organizational structure, training and operation
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Move towards mission level design: Mult.
Models of execution/Ptolemy architecture
CHALLENGES
Networked
Systems/Organizations
>100 Systems
>1000 ECUs/System
Linux, User behavior
Int. modeling of
arch/func/user
MLDesigner
- RTOS,HW,SW
- design process
- test
Performance level - operation
specifications,
reliability analysis
BONeS
Networked Componets
>100 ECUs
Multi-Disciplinary
Design
Single Discipline
Design
Year
Tool coupling
Integr. tools: Ctrl-C
MatrixX, Matlab
Mechanical CAD
Library based Sim
ACSL
1970s
VHDL, Verilog
1980s
Functional level
specifications
SPW/COSSAP
1990s
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
2000s
3
MLDesigner Software System
Common MLDesigner GUI, Block Diagram Editor and Kernal
XML Model Description, Simulation Control, CVS
Design Domains
Discrete Event
FSM/State Chart
Static Data Flow
Dynamic Data
Flow
Analog
NS2
SystemC
New ...
Libraries
Base Library
Add-on Libraries
802.11 MAC
Network Lib
Bus systems
...
User Libraries
Interfaces
Matlab
SatLab
Mathematica
Octave
GDB
Other Sim Tools
Other Applications
Hardware
OpenGL
Tcl/Tk
Altia
Conversion Util
BONeS => MLD
COSSAP => MLD
SystemC => MLD
UML => MLD
Ptolemy => MLD
MLD => C
MLD => SystemC
MLD => VHDL
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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MLDesigner Applications

Networked systems
OnChip, Avionics, Aircraft, RPV, AUV, Satellites, Cars, Comm., Networked
Computers (GRID), Large Scale IT Systems, Regional Conflicts, TTNT
Organizational, Design, Quality and Production Processes
Electronic system design
Embedded systems for controls, comm., …
Electronic and mechatronic SoC
Architectural performance level
Reconfigurable electronics
Reconfigurable FPGAs
Software radios
Soft redundancy
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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What are Large Scale Networked Systems?
 LSNS exhibit a complexity that can no longer be planned at a functional level
 When subcomponents, designed from written specifications, are assembled to the overall system,
the LSNS does not work. Hacking processes can only solve part of the problem
 Dynamic events couple subcomponents thru the network. Interactions between components and
reactions to dynamic events from the mission environment cannot be simulated functional or RTL
level
 Sufficient HIL tests are no longer feasible
 Major flaws in the design of such systems are not uncommon
 Problems are often both in the technical design process as well as the organizational process
 Examples include
 Global satellite communication systems (e.g., Teledesic failed)
 Integrated comm/nav systems
 Large scale IT systems
 Networked onboard ECUs
 Networked defense systems
 Organizational or production processes
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Requirements
Specifications
Scenarios
Transformation
Check
System Level Model
Network
Services
User
Equipment
Network
Equipment
Satellite
Equipment
Environment
Bus
On-Board
Processing
Voice
Data
Video
QoS
Traffic
Dish
Handheld
Protocols
Gateway
Routing
Access
NMS
Transponder
Switch
Antennas
Orbital
Mechanics
Radiation
Solar Flux
Rain
...
Solar Panel
Battery
Power Bus
Attitude +
Trajectory
Control
CPU/MEM/OS,…
Data Bus
Telemetry
...
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Critical Design Problems
V-Model
ESPITI-STUDY
Arch. Dev.
Spec/
Modeling
Critical problem
Implementation
0%
20 %
40 %
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
60 %
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Solution to The Challenge
Improving the quality of specification
Making specifications executable
Finding common Description language between engineering
disciplines
Testing functional level designs against executable
specifications
Integrating the design flow for design, test and
evaluation
Determining requirements for collaborative
organizational processes, qualification of engineers and
production processes
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Requirements for the design of LSNS
AVAILABLE TECHNOLOGY
Experience of engineers
Design technology/tools
Manufacturing technology
ENVIRONMENT
SYSTEM TO BE DESIGNED
USER REQUREMENTS
Other components
Inputs
Disturbances
Hardware
Operating System
Software
Function
Performance/Security
Usage
OUR REQUIREMENTS
MIN time-to-market/cost
Acceptable risk
Reusable components
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Mission Level Design Flow
MISSION LEVEL
ARCHITECTURE/
PERFORMANCE LEVEL
DE, FSM, CT
HW
SW
SW Performance
Estimation
Validation of
Implementation
HW DESIGN
SW DESIGN
HW
SW
FUNCTIONAL LEVEL
VALIDATION
IMPLEMENTATION LEVEL
(Verilog, VHDL, SystemC)
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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ML Design Flow with
UML-based SW Development
MISSION LEVEL
ARCHITECTURE/
PERFORMANCE LEVEL
DE, FSM, CT
HW
SW
SW
Performance
Estimation
SW Development
with UML
SW Development
with MLD
Automatic Code
Generation
Import into MLD > Verification
Validation of SW with HW/SW model
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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LSNS Examples
Air traffic management system for North Atlantic
Aeronautical communication system with hundreds of airplanes
US GRID
Country-wide automated toll collection/vehicle information system
Resource allocation for regional conflict
Large scale IT system
Tactical Target Network Technology
Global satellite system
Large scale onboard system
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Analysis of Requirements for ADS Communications
345
Aircrafts in
one direction
2 Inmarsat
satellites for
North
Atlantic
Worst Case
Analysis for
Inmarsat
GAN
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Worst Case Scenario for Inmarsat GAN
 Worst Case 345 Aircrafts within the Footprint
 Total Number of Aircraft flying from Europe to North America per day
 Mean Bandwidth Usage: 15 Mbps
 Maximum Bandwidth Usage: 17.7 Mbps
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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DARPA Program
Tactical Targeting Network Technology
(TTNT)
Adam Baddeley
Afeo.langley.af.mil/news/acticles/2004
http://www.rockwell.com/news/page5678.html
 “plug and play” tactical network extension to DoD Global Information Grid (GIG)





< 2 milliseconds
> 2 mbps
> 100 nm
3 sec ingress time for new nodes
> 2000 users
 Rockwell Collins: TTNT
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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DARPA Program
Tactical Targeting Network
Technology (TTNT)
 Over 3 years the simulation model has evolved from two-node prototype, to
a 1000-node system (air, ground, water)
 Simulation of communication between 1000 nodes would have taken
several month and exceeded the address space of 32 bit operating systems
 Update of simulator
 Removing object oriented data transport reduced memory requirements by more
than a factor 10
 New schedulers reduced simulation time, e.g., from 2 month to 30 min
 Dynamic instantiation
 Distributed simulation
=>Detailed performance level analysis identified protocol and interface
challenges that would otherwise been identified after hardware integration
=>High performance requires improvements at all levels of abstraction
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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TDM/WDM Pixel Bus Network Virtual Prototype
TDM
WDM
HCS-UFL/Rockwell Collins
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Model of architecture and function
TMLLF = Terrain Masking Low Level Flight
• Implementation on distributed processor
boards
• Communication with other systems over
network
• Modeled with MLDesigner for a TwoBoard-System of Level A and Level C
functions.
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Resource usage of parallel processors
Processing of loops
Resource VCU-Processor
Aktiver Prozess auf der VCU
Systemaktivität
Loop Ac tivity
VCU Ac tive Ta sk
Set
Set
Set
Set
Set
Set
Set
Set
80
70
60
0
1
2
3
4
5
6
7
Set 0
7
6
5
50
40
4
30
3
20
2
10
1
0
0
-10
-1
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
Zeit [10-4s]x10
0.0
-5
0.1
0.2
Set 0 3.0
Set 1
2.5
MLI
Senden
2.0
0.6
0.7
0.8
0.9
1.0
-4
x10
Aktive
Kanäle des MLI-Bus 1
MLI1 (0 Se nd , 1 Re c e ive )
MLI0 (0 Send , 1 Rec eive)
2.5
0.5
Resource MLI1-Chanels
Aktive Kanäle des MLI-Bus 0
MLI
Empfangen
0.4
Zeit [10-4s]
Resource MLI0-Chanels
3.0
0.3
2.0
1.5
1.5
1.0
1.0
0.5
0.5
0.0
0.0
-0.5
-0.5
-1.0
Set 0
Set 1
MLI
Empfangen
MLI
Senden
-1.0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Zeit
0.0
0.1
0.2
0.3
0.4
0.5
0.6
-4
[10-4s] x10
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
0.7
0.8
0.9
1.0
Zeit [10-4s]
20
-4
x10
HW in the loop tests
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Applying LSNS abstraction/simulation techniques to an
Automotive Power Management System model reduced
simulation times from > 1 month to several seconds
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Summary
For simulating high performance LSNS the simulation technology
had to be significantly improved in memory usage, speed and
robustness of schedulers and parallel execution. Models had to be
moved to higher levels of abstraction
Main experience with integrating design flow for LSNS from
application/mission to implementation
Reduced risk in design of complex systems because of validated
specifications
Reduced number of iterations in design
Project completion in time
Speedup of design/development of up to 10x and more
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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Questions?
http://www.mldesigner.com
HORST SALZWEDEL, PTOLEMY/KEPLER CONFERENCE MAY 12th, 2005
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