A Heterogeneous Approach for Wireless Network Simulations Jens Voigt Mobile Communications Systems Dresden University of Technology 01062 Dresden : (+49) 351 463 4246
: (+49) 351 463 7255
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1. Motivation: System Simulations of Mobile Cellular Networks 2. Wireless Network Simulator: Overview 3. Choosing a Model of Computation: Specifics of Mobile Cellular 4. Application: Simulation of a 60 GHz Indoor System Dresden U n i ve r s i t y o f Te c h n o l o g y
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
0
Mobile Communications Systems
System Simulations for Mobile Cellular Networks a network operator... has
limited
many users
must re-use the resources
number of resources causes
interferences
quality capacity
wants to offer needs
to balance the scales
buys
a Wireless Network Simulator (WiNeS)
Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
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3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
Wireless Network Simulator (1)
Overview
simulator configuration system-module (GSM)
WiNeS-core-classes
(interface definitions) WinesBase isA() getClassName()
system-module (60 GHz indoor)
1
WinesBaseInStar
WinesBaseInChannel
NE* myParent_p
Channel* myParent_p
getParent()
getParent()
getParent()
NetworkElement ExtSendQ myReadQ
...
1
WinesBaseInNE
DEStar* myParent_p
ExtSendQ myWriteQ -unsign. int myNum.
Channel
animation
BasePropagation
BaseMovement
ExtSendQ myAnswerQ handleReads() handleWrites()
BaseResourceOccupat.
BaseAntenna
-Position myPosition getNumber()
system-module (UMTS)
getPosition()
ExternSource
setNumber()
RefireQ myRefireQ
handleAnswers()
ExtSendQ myNewNEQ
BaseNetworkAccess
handleRefire()
InternSource BaseModem
RefireQ myRefireQ IntSendQ myTriggerQ handleRefire()
simulation control (Ptolemy-DE)
simulator Dresden U n i ve r s i t y o f Te c h n o l o g y
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
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Mobile Communications Systems
Wireless Network Simulator (2) Object-Oriented Analysis 1...n network inherent 0...n activities 1...n
data stream generator
resource maintenance 1...n
1...n
1...n backbone network
user activities
1...n
1
1
1...n
0...n
1 ... n
1
1
network element with fixed access
modem
network access
0...1
1
1 1 activation
resource usage
instantiates 1
1...*
1...n
1
transmission channel 1
1...n
movement
1...n radio wave propagation
antenna
1 1...n resource occupation
1...n
1...n
1
Dresden U n i ve r s i t y o f Te c h n o l o g y
resource allocation
1
1
1
Mobile Communications Systems
1...n
1
network element 1
1
environment
3
1
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
Model of Computation (1)
Multiple Layer Model system
channel
backbone network all network elements network element (prototype)
configuration
activation configuration
element .....
.....
.....
component
imperative
programming (WiNeS-classes)
other design environments (SDF, FSM,...)
other tools (Matlab™, SDT™,...)
Model of Computation can be different in each layer Dresden U n i ve r s i t y o f Te c h n o l o g y
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
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Mobile Communications Systems
Model of Computation (2)
Events on System Layer
backbone network
channel
many synchronous events
network elements activation
a few random events (e.g. poisson distributed)
NE Core
component 1 component 2
event-tags need not to be totally ordered through all layers Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
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3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
Model of Computation (3)
Channel Access
parallel
ordered in time ➔ multiple access technique technique ➔ logical control channels (e.g. a measure cycle)
➔ one transmission channel ➔ many network elements
channel
cell 1 cell 2 cell 3
cyclic
sequential ➔ channel access as
➔ an event cycle occurs
sequential process
Dresden U n i ve r s i t y o f Te c h n o l o g y
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Mobile Communications Systems
Model of Computation (4) synchronous timed system discrete event MoC
Alternatives communicating sequential processes
synchronous language CSP/π-/Fusion-calculus
➔ mutable system configuration possible
➔ fast compile time scheduling
➔ overspecifies model if applied in all layers ➔ run-time scheduling (overhead ≈10%) ➔ sequential DE has performance limits ➔ parallelization hard to implement
➔ number and order of events must not change
fits for random events works fine Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
➔ automatic scheduling based on rendezvous ➔ mutable system configuration and concurrency inherent in the model
➔ mutable system configuration ➔ random activation
fits for channel access not tried yet 7
➔ non-determinism use event cycle to get determinism? not tried yet 3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
Connection between Ptolemy and System-Modules Ptolemy
WiNeS-Core
stars as scheduler interface 1
System-Module implements methods
defines interfaces member
MoC dependent 1...n star
interface definitions in WiNeS-core are independent of MoC
1...n
calls methods in members 1 1 0...n porthole
Dresden U n i ve r s i t y o f Te c h n o l o g y
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
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Mobile Communications Systems
Application: 60 GHz System Module 11 00 11 00
11 00 11 00
11 00 11 00
virtual cell
office
office
11 00 11 00 11 00
office
hallway
1111 0000 1111 0000 1111 0000
1111 0000 1111 0000 1111 0000
base station
111 000 000 111
111 000 000 111
virtual cell
office
00 11 00 11 11 00 00 11 00 11 00 11 00 11 00 11 00 11
virtual cell office
1111 0000 0000 1111
hallway 111 000
virtual cell
office
11 00 00 11 00 11 00 11 00 11
base station
hallway
research project: campus network @ 60 GHz
base station
✔ each room == one cell ✔ system simulations in Generic Office Environment ✔ radiowave prediction by incorporated on-line Radiowave Propagation Simulator (RPS) ✔ different activation and mobility models Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
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3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
60 GHz System Module (1)
Layout
simulator configuration (VEM)
RPC
simulation (Ptolemy 0.x)
system layer Dresden U n i ve r s i t y o f Te c h n o l o g y
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
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Mobile Communications Systems
60 GHz System Module (2) Base-Stations:
HOFMap
System Configuration Mobile Stations:
DEDynMap
system configuration
element layer Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
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3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
60 GHz System Module (3) On-line Animation and Trace traced mobile resource occupation interference simulation (C++-Ptolemy 0.x)
CORBA™
animation (Java-Swing
and PtPlot)
link quality radiowave rays mobile’s path Dresden U n i ve r s i t y o f Te c h n o l o g y
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Mobile Communications Systems
3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt
Summary and Future Work - heterogeneous approach in three senses: -
different mobile cellular systems are modeled in different system modules
-
use of a Multiple Layer Model allows for a different MoC in each model layer
-
-
-
Event-Cycle for channel access allows for different MoC on system layer and simplifies parallelization
ready to use: -
two system modules (GSM and 60 GHz indoor)
-
simulation control: Ptolemy 0.7.1 - Discrete-Event Domain
-
on-line animation written in Java™ and connected via CORBA™
-
simulator configuration via Ptolemy0.x-GUI
plans: -
simulation control which allows for concurrency (first choice: base on PtolemyII CSP / PI)
-
more generic GUI for animation/configuration (use of DIVA system visualization?)
-
new system modules: 3G-UMTS, 4G-research project (IBMS)
Dresden U n i ve r s i t y o f Te c h n o l o g y Mobile Communications Systems
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3rd Ptolemy Miniconference UC Berkeley, 2/19/99 J. Voigt