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July.15, 2002 1
WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
1
WIRE-LAN TESTING OF WIRELESSNETWORK-CENTRIC SYSTEMS
July.15, 2002 2
WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
July.15, 2002 2
WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
July.15, 2002 3
WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
NETWORK-CENTRIC SYSTEMS
Command and Control
Police, Fireman and Ambulance
Air Traffic Control
Distributed Sensor Fusion
Mobile Agents
Network Adaptation
Layer 3 of Ad Hoc Networks“Effects of Wireless Physical Layer Modeling in Wireless Ad Hoc Networks”Takai, Martin, Bagrodia, MobiCom 2001.
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
CONCEPT
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
EMULATE DIGITAL RADIO TRANSMISSION
Station 1 Station 2
Wire Transmission(s)
Data/ Voice/ Video Packet
probe
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
B
8 Nodes Within LOS 6 Cells => 6 Datapoints (Multipath)
Mountain
SIMULATE RADIO PROPAGATION (TRANSMIT)
This NodeB
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
802.11 DCF EMULATION
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
SEGMENT FRAMES, EMULATE RADIO TRANSMIT SPEED
Data/ Voice/ Video Packet, Analog Xmssn
ProbeTrailer
Interframe gap computed to have last bit of the trailercoincide with the last bit of the emulated packet.
Where data is unimportant, e.g. background traffic, can send minimum-sized trailer to save bandwidth.
Other emissions (jamming, co-site, infared, optical)
Start/ChangeStop/Change
non-realtime simulation
EMULATION TYPE
1:
2:
3:
4:
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
SIMULATE COLLISIONS R
ea
l Tim
e
Transmit Part I
Receive Part I
Detect Collision
Transmit Part I
Receive Part I
Receive Part II Transmit Part II
Detect Collision
Station I Station II
ONLY ONE STATION COMPLETELY SENDS RADIO FRAME
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
CONSISTENT, DISTRIBUTED EMULATION
RANDOM SEED
probe
For multiple active probes, consistency rule guarantees all receivers choose the same random seed.
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
RANDOM SEED BRINGS FAIRNESS BACK TO COLLISION MODEL
ProbeTrailer Receiver Timeline
Time Of First Received Bit.
Random Seed Sets Virtual Receive TimeWithin These Limits.
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
DEMONSTRATION
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
13
WIRELESS NETWORK SIMULATION:
DEMONSTRATION LAN
10 Base T
Linux 2.2.15
Uses Ordinary PC Components + Software + Modified Driver For 3 Com Ethernet III Card
i586 i586 i586 i686
i686 i686 i686
Two Drops Required For Identical Receive Ordering
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
APPROXIMATE WIRELESS LAN THROUGHPUT
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
SATURATION THROUGHPUT
550
600
650
700
750
800
850
610623
721714
812812
906912
10321026
Offered Traffic, Kbit/s
Thr
ough
put,
Kbi
t/s
Tests, Five PCs
Bianchi, Five Stations
Tests, Seven PCs
Bianchi, Seven Stations
Five PCsSeven PCs
Emulation ParametersData Length 1024 octetsMAC header 34 octetsChannel Bit Rate 1 Mbit/sSIFS 28 sSlot Time 50 sACK length 30 octetsPHY header 16 octetsPropagation delay 1 sDIFS 130 s
10 9.810 9.8max, avg frames delivered (1,000)
Five PCsSeven PCs
10 9.810 9.8
10 9.55.3 4.9
6.7 6.58.6 7.6
10 9.310 8.7
1.23 1.221.3 1.27max avg
1.23 1.231.32 1.31
1.25 1.241.31 1.30
Five PCsSeven PCs
Average Number Attempts Per Frame (Bianchi - 1.22, five stations)
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
1.23 1.221.3 1.27max avg
1.23 1.231.32 1.31
1.25 1.241.31 1.30
Five PCsSeven PCs
Bianchi - 1.22, five stations
AVERAGE ATTEMPTS PER FRAME
812812
906912
10321026
Offered Traffic(Kbit/s)
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
VARY CONTENTION WINDOW (SATURATION)
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
EXISTING APPROACHES
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
PACKET KILLER (CMU MONARCH PROJECT, …)
Receiver Filters MAC Source Address From List of Prohibited Addresses
Trace File (List Of Prohibited Addresses) Created Beforehand
Trace File Based On External Simulation/Experimentation Measurements
Some Practitioners Say Ethernet Good Enough To Represent Radio’s Collision-Based MACHOWEVER: Measured saturation throughput for 2 to 24 stations on
Ethernet exceeds 95 % utilization for 1024 octet packets. (Boggs, Mogul, Kent, ACM SIGCOMM ‘88). Bianchi demonstrates 80% saturation throughput for CSMA/CA with 5 stations.
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
STORM Federation (HLA)
SimulateRadioPropagation
SimulateNodalPositions
SimulateNodalPositions
(1) (1)
Both Receiver and Propagation Receive Data Message (1).
SimulateRadioPropagation
SimulateNodalPositions
SimulateNodalPositions
Receiver’s Emulated Radio Holds Data Message (1). Until It Receives Release-Packet (2) From Propagator.
(1)
(2)
Propagator
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
DIS Transmission Characteristic Packet
Transmission Characteristics Packet (1) Sent Prior to Data Packet (2).
Receiver Computes and Adjusts Timing and Reception Characteristics.
TADL Working Group Migrating DIS to HLA.
Other DIS Models:
Intercom
Electromagnetic Emission (Jamming), Designator (Cosite), Underwater Acoustic, IFF/ATC/NAVAIDS, Supplemental Emission/Entity State.
SimulateNodalPositions
SimulateNodalPositions
(1)(2)
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WIRELESS NETWORK SIMULATION:
GENERAL DYNAMICSC4 Systems
COMPARISON (FOR REAL-TIME EMULATION)
Segmented Radio Frame (This Paper)
STORM (HLA)
Transmission-Characteristic
Frame (DIS/HLA)
Modifications To Tested System - + -
Congestion + - - Collision Model ++ - -
Large System Emulation - Wide-Area
Testing/Training -