1. Small-Scale and Large-Scale Routing in Vehicular Ad Hoc Networks Wenjing Wang 1, Fei Xie 2 and Mainak Chatterjee 1 1 School of Electrical Engineering and Computer Science, University of Central Florida 2 Department of Computer Science, Portland State University IEEE Transactions on Vehicular Technology, VOL. 58, NO. 9, November 2009 TVT 2009

2. 48 2 Outline Introduction Introduction Related Work Related Work Vehicular Mobility Models Vehicular Mobility Models Routing in Small-scale VANETs Routing in Small-scale VANETs  Connection-based Restricted Forwarding  Connectionless Geographic Forwarding Routing in Large-scale Vehicular Ad Hoc Networks Routing in Large-scale Vehicular Ad Hoc Networks  TOPO Performance Evaluation of TOPO Performance Evaluation of TOPO Conclusion Conclusion

3. 48 3 Introduction Due to the cost and difficulty associated with the implementation of VANETs in the real world Due to the cost and difficulty associated with the implementation of VANETs in the real world  Computer Simulations Many studies on mobile ad hoc networks (MANETs) have used Many studies on mobile ad hoc networks (MANETs) have used  Random WayPoint (RWP)  Manhattan Model

4. 48 4 Introduction Modeling mobility for vehicular ad-hoc networks Modeling mobility for vehicular ad-hoc networks  ACM VANET 2004 TIGER: Topologically Integrated Geographic Encoding and Referencing System TIGER: Topologically Integrated Geographic Encoding and Referencing System

5. 48 5 Introduction Routing Problem Routing Problem  Small Areas (e.g., less than 1 mi 2 ) 1) Connection-based Restricted Forwarding (CBRF) 1) Connection-based Restricted Forwarding (CBRF) 2) Connectionless Geographic Forwarding (CLGF) 2) Connectionless Geographic Forwarding (CLGF)  Large Areas (e.g., tens of the mile scale) Two-phase Routing Protocol (TOPO) Two-phase Routing Protocol (TOPO)

6. 48 6 Related Work Mobility models in MANETs are not suitable for VANETs Mobility models in MANETs are not suitable for VANETs  Macro (e.g., Road Information and Traffic Information)  Micro (e.g., Driver Behavior) Modeling Mobility in VANETs Modeling Mobility in VANETs  1) Analysis Highways Highways Residential Area Residential Area  2) Simulation CORSIM CORSIM

7. 48 7 Vehicular Mobility Models TIGER Data Files TIGER Data Files  A road is defined by two intersections it has with other roads Road 1 Road 2

8. 48 8 Vehicular Mobility Models A. Road Mobility Model A. Road Mobility Model  On any road, the mobility of vehicles is constrained by the posted speed limit 15 mi/h (24 km/h) 15 mi/h (24 km/h) 35 mi/h (56 km/h) 35 mi/h (56 km/h) 55 mi/h (88 km/h) 55 mi/h (88 km/h) 60 mi/h (96 km/h) 60 mi/h (96 km/h) 75 mi/h (120 km/h) 75 mi/h (120 km/h)

9. 48 9 Vehicular Mobility Models A. Road Mobility Model A. Road Mobility Model  1) d m Speed Limit ± 5 mi/h

10. 48 10 Vehicular Mobility Models A. Road Mobility Model A. Road Mobility Model  2) d m 50 m Overtake Probability p Speed Up 5 mi/h Faster

11. 48 11 Vehicular Mobility Models A. Road Mobility Model A. Road Mobility Model  3) Safe Distance (Usually 2-s Distance) Not to Overtake

12. 48 12 Vehicular Mobility Models B. Intersection Mobility Model B. Intersection Mobility Model When a vehicle approaches an intersection, it follows the intersection mobility rules given here. When a vehicle approaches an intersection, it follows the intersection mobility rules given here.  1) Deceleration a 50 m STOP

13. 48 13 Vehicular Mobility Models B. Intersection Mobility Model B. Intersection Mobility Model  2) Maximum Stop Time at Intersections Stop Sign Traffic Light 55mi/h60mi/h STOP 35mi/h 15mi/h

14. 48 14 Vehicular Mobility Models B. Intersection Mobility Model B. Intersection Mobility Model  3) Acceleration b

15. 48 15 Routing in Small-scale VANETs A. Implementation A. Implementation  1000-m × 1000-m Square Areas in Orlando, FL 1) Downtown “Grid” Area 1) Downtown “Grid” Area 2) Residential Area 2) Residential Area  TIGER  The Trace for Vehicle Movements: 1000s  Randomly Chosen Source and Destination Spots on the Roads  Dijkstra’s Single-source Shortest-path Algorithm  Adding Traffic Lights and Stop Signs Intervehicle Distance Overtaking Probability Acceleration Deceleration d = 50m p = 0.5 a = 4 m/s 2 b = -4 m/s 2

16. 48 16 Routing in Small-scale VANETs TIGER TIGER

17. 48 17 Routing in Small-scale VANETs Average speeds of vehicles in residential and downtown areas applying different mobility models Average speeds of vehicles in residential and downtown areas applying different mobility models  Car-following Model STreet RAndom Waypoint (STRAW)

18. 48 18 Routing in Small-scale VANETs Average speeds of vehicles in residential and downtown areas with different mobility parameters Average speeds of vehicles in residential and downtown areas with different mobility parameters d = 20m p = Random a = 2 m/s 2 No Overtaking Downtown Area Residential Area

19. 48 19 Routing in Small-scale VANETs B. Inapplicability of MANET Routing Protocols B. Inapplicability of MANET Routing Protocols  To update the routing tables, a huge amount of information exchange is needed, making large overhead a burden for the network.  Two Proposed Routing Protocols Based on AODV AODV GPSR GPSR  All Vehicles GPS GPS Wireless Transceivers Wireless Transceivers  Some Communication Range and Direction

20. 48 20 C. CBRF (Connection-based Restricted Forwarding) C. CBRF (Connection-based Restricted Forwarding)  The CBRF algorithm works like AODV Route Request (RREQ) Route Request (RREQ) Route Reply (RREP) Route Reply (RREP) Routing in Small-scale VANETs Source Destination RREQ RREP

21. 48 21 C. CBRF C. CBRF Routing in Small-scale VANETs Source Destination Data RERR

22. 48 22 C. CBRF C. CBRF  Restricted Forwarding Routing in Small-scale VANETs

23. 48 23 Routing in Small-scale VANETs D. CLGF (Connectionless Geographic Forwarding) CCCCLGF follows the same routine as GPSR CCCCongestion caused in GPSR A  C B  D Hotspot Node 1-D

24. 48 24 Routing in Small-scale VANETs D. CLGF D. CLGF  Level of Congestion Information Queue Length / Total Buffer Size Queue Length / Total Buffer Size Periodically Hello Packets Identifier Position Level of Congestion Level of Congestion Threshold: 0.8

25. 48 25 Routing in Small-scale VANETs E. Simulation Model and Setup E. Simulation Model and Setup  NS2-based (version 2.28) Wireless Signal Frequency 5.9 GHz Bandwidth 10-MHz Fixed Transmission Powers 20.4 dBm Communication Range 400 m DSRC Receiver Sensitivity −77 dBm Data Rate 6 Mb/s Simulation Time 900s Number of Vehicles 50 ~ 250 Packet Size 64 B

26. 48 26 Routing in Small-scale VANETs E. Simulation Model and Setup   In CBRF 250 150

27. 48 27 Routing in Small-scale VANETs F. Performance Study AODV CBRF

28. 48 28 Routing in Small-scale VANETs F. Performance Study AODV CBRF

29. 48 29 Routing in Small-scale VANETs F. Performance Study AODV CBRF

30. 48 30 Routing in Small-scale VANETs F. Performance Study GPSR CLGF

31. 48 31 Routing in Small-scale VANETs F. Performance StudyGPSR CLGF

32. 48 32 Routing in Small-scale VANETs G. Impact of Road Layouts and Mobility AODV CBRF Downtown Residential

33. 48 33 Routing in Small-scale VANETs G. Impact of Road Layouts and Mobility G. Impact of Road Layouts and Mobility d = 20m p = Random a = 2 m/s 2 No Overtaking Downtown Area Residential Area

34. 48 34 Routing in Small-scale VANETs G. Impact of Road Layouts and Mobility G. Impact of Road Layouts and Mobility d = 20m p = Random a = 2 m/s 2 No Overtaking Downtown Area Residential Area

35. 48 35 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks A. Definitions: Overlay and Access A. Definitions: Overlay and Access  Overlay High-density High-speed Limit Roads (e.g., State Roads and Interstate Roads) High-density High-speed Limit Roads (e.g., State Roads and Interstate Roads)  Access The Remaining Roads (e.g., Residential Areas and Low-speed Roads) The Remaining Roads (e.g., Residential Areas and Low-speed Roads)

36. 48 36 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks A. Definitions: Overlay and Access A. Definitions: Overlay and Access  Neighbor List Neighbor IDs Neighbor IDs Next Intersection IDs Next Intersection IDs Current Phase Current Phase  Access  Overlay

37. 48 37 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks B. Two-Phase Routing Scheme B. Two-Phase Routing Scheme SourceDestination AccessAccess AccessOverlay OverlayAccess OverlayOverlay 1km 1km 1km 1km 1km 1km 1.5km

38. 48 38 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks C. Access Routing Phase C. Access Routing Phase CLGF CBRF

39. 48 39 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks D. Overlay Routing Phase D. Overlay Routing Phase  1)  2)  3) BA Overlay KCar GCar M TTL F Overlay KCar GCar M Carr y

40. 48 40 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks TOPO TOPO Destination CLGF CBRF Source

41. 48 41 TOPO: Routing in Large-scale Vehicular Ad Hoc Networks E. ITS Friendliness E. ITS Friendliness  There are N traffic flows with weights w 1, w 2,..., w N, the data rate for flow i is given by  where R is the available link data rate

42. 48 42 Performance Evaluation of TOPO GTNetS (50,000 nodes in a mobile ad hoc scenario) GTNetS (50,000 nodes in a mobile ad hoc scenario) Area 10 km × 3 km Number of Nodes 6000 Dijkstra’s Single-source Shortest Path Algorithm The Presented Mobility Model Separation Distances 2000, 3000, 4000, and 6000 ± 50 m TTL Level of Congestion Threshold 0.8 3s

43. 48 43 Performance Evaluation of TOPO A. Performance A. Performance

44. 48 44 Performance Evaluation of TOPO B. Effect of Packet Size and Packet Rate B. Effect of Packet Size and Packet Rate

45. 48 45 Performance Evaluation of TOPO C. Effect of Vehicle Density C. Effect of Vehicle Density  2000, 6000, and 8000 vehicles (66.7, 200, and 266.7 vehicle/km2)

46. 48 46 Performance Evaluation of TOPO D. Effect of Packet Caching D. Effect of Packet Caching

47. 48 47 Performance Evaluation of TOPO E. Performance Under ITS E. Performance Under ITS  w = (weight of ITS / weight of the TOPO) fix w = 2

48. 48 Conclusion This paper proposes a vehicular mobility model based on real-life scenarios This paper proposes a vehicular mobility model based on real-life scenarios This paper proposes two small-scale VANET routing schemes and carefully studied their performance This paper proposes two small-scale VANET routing schemes and carefully studied their performance  Connection-based Restricted Forwarding (CBRF)  Connectionless Geographic Forwarding (CLGF) This paper proposes a large-scale VANET routing schemes This paper proposes a large-scale VANET routing schemes  Framework   ITS Friendliness

49. 48 49 Thank you Thank you