Department of Electrical and Computer Engineering The Ohio State University 1 Evaluation of Intersection Collision Warning System Using an Inter-vehicle Communication Simulator Atakan Doğan, Gökhan Korkmaz, Yiting Liu, Füsun Özgüner, Ümit Özgüner, Keith Redmill, Oscar Takeshita, K. Tokuda
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Evaluation of Intersection Collision Warning System Using an Inter-vehicle Communication Simulator
Evaluation of Intersection Collision Warning System Using an Inter-vehicle Communication Simulator. Atakan Do ğ an, Gökhan Korkmaz, Yiting Liu, Füsun Özgüner, Ümit Özgüner, Keith Redmill, Oscar Takeshita, K. Tokuda. Outline of Contents. Introduction Vehicle Traffic Simulator Shadowing Effect - PowerPoint PPT Presentation
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Department of Electrical and Computer Engineering
The Ohio State University 1
Evaluation of Intersection Collision WarningSystem Using an Inter-vehicle CommunicationSimulator
Atakan Doğan, Gökhan Korkmaz, Yiting Liu,
Füsun Özgüner, Ümit Özgüner, Keith Redmill, Oscar Takeshita, K. Tokuda
Department of Electrical and Computer Engineering The Ohio State University 2
Department of Electrical and Computer Engineering The Ohio State University 12
Simulation Setup Screen
Scenario Input
Traffic Flow Characteristic Input
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Vehicle Management
Turning
NormalDriving
Vehicle Following
Vehicle Management
Driver information:
• Its own speed• Its own position data from DGPS• Turning direction• Other vehicles in Line-of-sight and the estimated distance and speed• Status of traffic lights
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Traffic Light Management
Scenario Input
Cycling Time
Direction
Status
Cycling Time( Two Phase):
G=25sec;Y=5sec
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Message Generator
Initialdataupdate
Transmissionintervals
Retransmissionattempts
Send messages when vehicle crosses initial data update border
Distance-based Transmissions
50 meters
Vehicle Characteristics
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Department of Electrical and Computer Engineering The Ohio State University 17
Shadowing
TX RX
Block
TX
RX
Block
Blocking area
h
d1 d2
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Shadowing Fresnel-Kirchoff diffraction parameter:
21
21
dd
)d2(dh
Using the Fresnel integral,
4.2),5/20log(0.22
4.21,)1.038.0(1184.020log(0.4
10),20log(0.5e
01),0.6220log(0.5
1,0
ψ(dBm)2
0.95
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Shadowing (Adjacency Matrix)
ε = 0 ε12 ε13 … …
ε21 0 … … …
ε31 … 0 … …
… … … … …
… … … … 0Note:• ε ij diffraction gain (in dB) for receiver j from transmitter i. •This is a symmetric matrix.•Both negative and positive gains are possible.
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Outline of Contents
Introduction Vehicle Traffic Simulator Shadowing Effect The Wireless Simulator
• MAC Layer• Physical Layer
Simulations Conclusions
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WS Process Structure
Main process: initialization, termination, VTS interface, etc.
Each process (except Main) implements MAC and PHY layers
All processes run in parallel in the simulated time
MainProcess
Process 1
Process 2
Process 3
Process n
n: no of vehicles
MACPHY
MACPHY
MACPHY
MACPHY
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MAC Layers 802.11 CSMA/CA
802.11a, 802.11b, and 802.11a R/A are implemented
RTS, CTS, and ACK packets are not implemented because
Broadcast Application => More than one destination
Short Data Packets
Nodes wait DIFS amount of time before sending their packets
If nodes sense the channel busy, they wait a random amount of time
DOLPHIN Non-persistent CSMA
5 retransmissions
Vehicles transmit one packet in each slot
slot length = 20 msec
5 retransmissions
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PHY Layer
Path loss, shadowing, and fading: Modeled
Carrier sensing and capture: Modeled
Noise: Cumulative Signal reception: SNR threshold based
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Signal PowerA packet will be received when the received signal power is larger than the threshold.The received signal power is computed as:
ψ(dBm)PL(dBm)(dBm)P(dBm)P tr
er transmittat thepower signal :(dBm)t
P
losspath :PL(dBm)
receiver at thepower signal :(dBm)r
P
shadowing :ψ(dBm)
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Fading Gilbert-Elliot model:
Good Bad
Pgb
Pbg
Pge: bit error probability in Good state
Pbe: bit error probability in Bad state
1-Pgb 1-Pbg
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Simulation time
Wireless repeater
Building location
Truck
Bus
Motorcycle
Car
Intersection Type •Traffic signal
• North – South•Stop sign
Last message
Critical messages
Last collision
Transmitter
Receiver
ReceiverCollision warning
Motorcycle
Simulation Results
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Simulation Results
Performance metric for Wireless Communication
packetsdtransmitteofnumberTotal
packetsdtransmittelySuccessfulRateSuccessPacket
____
____
For a packet to be treated as successful, it should be received by ALL receivers in the region. Even if one vehicle can not hear the transmission, this packet is treated as unsuccessful.
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Simulation Results
Dolphin at 0.5 Mbps
10.9900.997Right angle
10.9930.996Left turn
light
10.9920.996Right turn
10.9830.995Left turn
MaximumMinimumMeanScenario
Packet Success Rate
10.9900.997Right angle
10.9930.996Left turn
light
10.9920.996Right turn
10.9830.995Left turn
MaximumMinimumMeanScenario
Packet Success Rate
802.11 a R/A, left turn(Similar Results for other Scenarios)
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