RPB-MD: A Novel Robust Message Dissemination Method for VANETs Congyi Liu and Chunxiao Chigan...
-
Upload
stanley-lawson -
Category
Documents
-
view
216 -
download
0
description
Transcript of RPB-MD: A Novel Robust Message Dissemination Method for VANETs Congyi Liu and Chunxiao Chigan...
RPB-MD: A Novel Robust Message Dissemination Method for VANETs
Congyi Liu and Chunxiao ChiganMichigan Technological University
GLOBECOM 2008
Outline Introduction RPB-MD:
Relative Position Based Message Dissemination Performance Evaluation Conclusion
Introduction VANETs providing multi-hop wireless communic
ation among vehicles, promises a broad applications.
Robust message disseminations are desirable for most of safety-critical VANET applications.
Related Work To disseminate messages by delaying different
times to avoid peak load This scheme requires location service and does not
consider the issue of partitions, which may affect the delivery ratio significantly.
Carry and forward Would result in high overhead (especially under the
dense vehicular traffic), and high computation complexity because of the process of partition crossing.
Related Work (cont.) Considered the direction of vehicle movement to
disseminate messages. Can not ensure robust message dissemination.
Goal In this paper, we address the issue of robustly
disseminating messages to all intended vehicles in the zone-of-relevance.
Zone-of-relevance defines the area where the message is of interest to the drivers.
The design of such mechanisms aims at high message delivery ratio with acceptable latency and overhead.
Assumptions We can get the precise relative distance between two
neighbors (i.e. Based on received signal strength indication, RSSI.)
The reference direction ,which is used as a basis for the comparison of vehicles’ directions, can also be achieved in the highway scenario.
Assume that two directional antennas are equipped for every vehicle to communicate with each other within 180o
RPB Forwarding Strategy - Overview
A
C
B D F
E
A
C
F
Message Head
Message Head
Message HeadActive State
Active State
Active StateIntermediate State
Intermediate State
Inactive StateActive StateIntermediate State
Intermediate StateActive State
Intermediate StateActive StateInactive StateMessage Holder
Message Holder
Message Holder Message Holder
Message Holder
Implicit ACKExplicit ACK
The Next Candidate Message Head
The Next Candidate Message Head
A
C
B
)3005.010080(
11
e
)3005.010080(
11
e
67.002.03002508.0 iW
6.012.03001508.0 iW
msmsTi 65.1)67.01(5
msmsTi 2)6.01(5
Hold the message further with probability
iP iPλ
Message Head abnormal modes handling – case1
A
C
BA
C
B
Message Head abnormal modes handling – case2 (t1)
A
C
BAD
)1(50150100080
36002
emsTi
E
)1(50200100080
36002
emsTi
D
Message Head abnormal modes handling – case3 (t2)
A
C
BAD
C
Message Holder abnormal modes handling – case1(T’)
A
C
BAD
msmsTi 7.1630010050
B
msmsTi 3.3330020050
Message Holder abnormal modes handling – case2 (t3)
A
C
BAD
msmsTi 7.1630010050
B
msmsTi 3.3330020050
Addressing Model
r
Update of the total relative distance
Update of total relative distance
A A B
Simulation Parameter
Parameter Value
802.11 DCF data rate 2Mbps
Communication Range 250m
Number of lanes 2/direction
Vehicle density 5-100 cars/(km。 lane)
Average speed 90km/h
Waiting time T0 50ms
Waiting time T’ 1s
Waiting time t1 2s
Waiting time t2 2.5s
Waiting time t3 3s
Simulation model 12km
Distance from S to D 6.5km
message size 512bytes
Simulator ns-2 (version 3.31)
Comparison: Epidemic routing M. Nekovee, and B.B. Bogason, “Reliable and Efficient
Information Dissemination in Intermittently Connected Vehicular Adhoc Networks,” Proceedings of IEEE Vehicular Technology Conference, pp.2486–2490, April 2007.
A. Vahdat, and D. Becker, “Epidemic Routing for Partially Connected Ad Hoc Networks,” Technical Report CS-200006, 2000. http://issg.cs.duke.edu/epidemic/epidemic.pdf
Conclusion This paper proposed a novel relative position base
d message dissemination scheme for VANETs.
The scheme can ensure robust message dissemination and desirable performance under all VANET traffic densities.