connectivity aware routing for vehicular ad hoc networks l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Connectivity Aware Routing for Vehicular Ad Hoc Networks PowerPoint Presentation
Download Presentation
Connectivity Aware Routing for Vehicular Ad Hoc Networks

Loading in 2 Seconds...

play fullscreen
1 / 30

Connectivity Aware Routing for Vehicular Ad Hoc Networks - PowerPoint PPT Presentation


  • 540 Views
  • Uploaded on

Connectivity Aware Routing for Vehicular Ad Hoc Networks Qing Yang, Alvin Lim, Prathima Agrawal Auburn University IEEE Wireless Communications & Networking Conference March 31 – April 3, 2008, Las Vegas Outline Goals Basic concepts Related works Assumptions Model of the connectivity

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Connectivity Aware Routing for Vehicular Ad Hoc Networks


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
connectivity aware routing for vehicular ad hoc networks

Connectivity Aware Routing for Vehicular Ad Hoc Networks

Qing Yang, Alvin Lim, Prathima Agrawal

Auburn University

IEEE Wireless Communications & Networking Conference March 31 – April 3, 2008, Las Vegas

outline
Outline
  • Goals
  • Basic concepts
  • Related works
  • Assumptions
  • Model of the connectivity
    • Validation with VanetMobiSim
  • Routing strategy
  • Simulations and result analysis
  • Conclusions

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

goals
Goals
  • Achieves routing between two ends

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

basic concepts
Basic concepts
  • Model the probability of connectivity of each road segment
  • Find the route with the highest probability of connectivity
  • Carry-and-forward the packet while facing network partitions

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

related works
Related Works
  • VADD (’06Infocom)
    • Vehicle-Assisted Data Delivery
  • MURU (’06MobiQuitous)
    • Multi-Hop Routing for Urban Vanet
  • GSR (’05MC2R)
    • Geographic source routing
  • GPSR (’00MobiCom)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

assumption
Assumption
  • GPS on each vehicle
    • Standard component
  • Digital maps [1,2]
    • Vehicle density
    • Vehicle speed
    • Traffic light period

1. http://www.mapmechanics/

2. http://www.yahoo.com/

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

model of connectivity

….

n cars

n0 cells

m cells

Model of connectivity
  • One lane road segment
    • road segment (length is L) is equally divided into m cells
    • each cell can contain only one node
    • communication range is size of n0 cells

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

multiple lanes case

….

….

Multiple lanes case
  • One lane road segment
    • Number of empty cells is m-n
  • Multiple lanes road segment
    • Number of lanes is n’
    • Number of empty cells ranges [m-n, m-n/n’]

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

problem formulation

….

Problem formulation
  • Problem formulation
    • What is the probability that network is connected
    • The probability that no gap in networks is larger than the communication range
  • Random Allocation (RA) theory

1

0

0

1

1

0

1

2

0

1

1

1

1

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

probability of connectivity
Probability of connectivity
  • P1 (exists exactly k empty cells)
  • P2 (exists more than n0continuous empty cells)
  • Pcon (Probability of connectivity)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

vanetmobisim
VanetMobiSim
  • Feature
    • multi-lane roads
    • separate directional flows
    • traffic signs at intersections
    • Intersection management
    • Lane changing
  • VanetMobiSim[3] mobility patterns have been validated against TSIS-CORSIM
    • a well known and validated traffic generator

3. http://vanet.eurecom.fr

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

validation of connectivity model
Validation of connectivity model
  • Length of road
    • 1000m, 1800m
  • Traffic light period
    • 60sec., 120sec.
  • Average velocity
    • 7.5m/s, 10m/s

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

result of validation
Result of validation
  • 1000m, 7.5m/s and 60sec

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

result of validation cont
Result of validation (cont’)
  • 1800m, 10m/s and 120sec

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

probability of connectivity of route
Probability of connectivity of route

p3

p8

  • Pi: probability of connectivity of road segment i
  • Pcon: probability of connectivity of selected route (path)
    • Defined as ∏Pi

p1

p11

p6

p4

p9

p1*p4*p7*p12=Max?

p2

p7

p12

p5

p10

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

computation of pr
Computation of Pr
  • Define of Pr:
    • sequence of road segments from source to destination
  • Modified Dijkstra Algorithm
    • Final goal: maximize the probability of whole path
    • Each step: add one more edge, the probability of new path decrease
  • Can be computed
    • Centralized
    • Distributed

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

computation of pr cont
Computation of Pr (cont’)
  • Centralized
    • Path Pr was computed only by source node
    • Size of packet header is proportionate to hop number
  • Distributed
    • Every node who received packet computes Pr
    • More processing on vehicles

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

routing strategy
Routing strategy
  • Compute Pr
  • Find hops on road segment along Pr
    • Every node beacons its current position
    • Predict neighbor’s position while choosing next hop
  • Carry and forward
    • Buffered packet if no available next hop
    • Send buffered packet when new next hop is in range

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

carry and forward strategy
Carry and forward strategy
  • Buffer packets which cannot be forwarded
  • Send out buffered packet if new next hop is available
  • Good for VANET
    • Lots of “holes” in VANET
    • On path Pr, higher probability of obtaining a new next hop
    • Big buffer is feasible in cars

Wisitpongphan, N.; Bai, F.; Mudalige, P.; Tonguz, O. K., "On the Routing Problem in Disconnected Vehicular Ad-hoc Networks," INFOCOM 2007. 26th IEEE International Conference on Computer Communications. IEEE , vol., no., pp.2291-2295, May 2007

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

simulation
Simulation
  • Nodes movement
    • VanetMobiSim
  • Map
    • TIGER/LINE
    • Real map from Tennessee
  • Network simulation
    • Ns2 setup
    • Result analysis

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

map information
Map information
  • TIGER[4]
    • Topologically Integrated Geographic Encoding and Referencing
  • A format used by the United States Census Bureau to describe land attributes
    • Roads, buildings, rivers, and lakes
    • Can be read by Tivec[5]

4. http://www.census.gov/geo/www/tiger/

5. http://www.triusinc.com/latest.htm

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

map in simulation
Map in simulation
  • Centered at
    • Long: -84877562
    • Lat: 35162102
  • Size
    • Width: 2000m
    • Length: 2000m

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

ns2 setup
Ns2 setup
  • Simulation Area: 2000m*2000m
  • Number of nodes: 100, 200
  • Communication range: 250m
  • Packet size: 512 Byte
  • CBR rate: 0.1 ~ 1packet/sec.
  • Random selected source and fixed destination
  • Buffer size: 64kBytes
  • Beacon interval: 1.0 sec.
  • Velocity: 15 ~ 35 MPH

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

data delivery ratio 100nodes
Data delivery ratio (100nodes)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

data delivery ratio 200nodes
Data delivery ratio (200nodes)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

networking delay 100nodes
Networking delay (100nodes)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

networking delay 200nodes
Networking delay (200nodes)

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

throughput
Throughput

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

conclusions
Conclusions
  • Connectivity issue is very important in VANET
  • CAR performs well and is independent on the network density
  • Perimeter mode of GPSR suffers in frequently disconnected networks

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008

questions and comments
Questions and comments

Thanks!

IEEE Wireless Communications & Networking Conference (WCNC), Las Vegas, 2008