Road-Based Multipath Routing in Urban VANETs 都會區車輛隨意網路之多重路徑繞徑技術

Copyright © 2012, [email protected]

Road-Based Multipath Routing in Urban VANETs

都會區車輛隨意網路之多重路徑繞徑技術

指導教授：王國禎博士學生：鍾昆佑國立交通大學網路工程研究所行動計算與寬頻網路實驗室

1


Outline

• Introduction• Related work• Background• Proposed road-based multipath routing• Simulation and discussion• Conclusion and Future work • References

2


Introduction

• Vehicular Ad Hoc Networks (VANETs) consist of mobile vehicles (nodes) , and each node moves arbitrarily and communicates with others by wireless links

• Wireless links would be broken frequently because of high mobility in VANETs

• In urban VANETs , each node moves in constrained areas independently

3


Introduction

• Ad-hoc on-demand distance vector (AODV) [1] and dynamic source routing (DSR) [2] are two most widely studied on-demand ad hoc routing protocols which are node-centric

• The traditional node-centric view of the route leads to frequent broken routes in the presence of VANETs’ high mobility [3]

4


Introduction

5

• Node-centric problem [3]

N2S

N1

SD

N1

DN2

(a) At time t (b) At time t + a

A1 A1


Introduction

• One alternative approach, geographical routing, is offered by geographical routing protocols, e.g., greedy–face–greedy (GFG) [4] and greedy other adaptive face routing (GOAFR) [5]

• Since dead end roads exist in Urban VANETs, geographical routing protocols do not always perform well

6


Introduction

• Geographical routing problem [3]

7

S

N2

N3 D

Dead end road

N1


Introduction

• RBVT [3] proposed a road-based VANET routing protocol that leverages real-time vehicular traffic information to create road-based routing paths

• There are many single path routing protocols, which need to create a new route when a path breaks

8


Introduction

• Multipath routing creates many paths from sender to receiver

• If one route disconnects, sender can choose other routes to transfer packets

• Multipath routing can classify two types : node-disjoint routing and link-disjoint routing [6]

9


Introduction

• Node-disjoint routes (a) and link-disjoint routes (b)

10

D

A B

M N

S

(a) Node-disjoint routes

D

A

M

S

(b) Link-disjoint routes

B

C

N


Introduction

• In [7], the authors have proved node-disjoint multipath routing is better than link-disjoint multipath routing in terms of packet delivery ratio

• We propose a road-based multipath routing (RBMR) , which is node-disjoint

11


Introduction

• We propose a road-based multipath routing (RBMR) , which is node-disjoint– It focuses on establishing two fast routes from sender

to receiver– It begins to send packets once a fast route is

established– The slow route which is established later will be used

if the first route is disconnected– To the best of our knowledge, there is no existing

road-based multipath routing protocol

12


Related work

• Connectionless approach (CLA) [8] is a road-based single path routing protocol

• It records road segments instead of nodes

• Ad-hoc on-demand multipath distance vector routing (AOMDV) [9] , which is link-disjoint, creates several paths from source to destination, and packets are sent after paths established

13


Related work

• NDMR [10] is a node-centric, node-disjoint multipath routing– It sends packets after creating one path, but it is a

node-centric routing protocol, so the route is easy to be disconnected than that of the road-based routing protocol

14


Related work

Routing method

CLA [8]

AOMDV [9]

NDMR [10]

RBMR (proposed)

Path counts 1 ≧2 2 2

Node- centric or Road-based

Road- based

Node-centric

Node-centric

Road-based

Node- disjoint or Link- disjoint

-( Single path routing )

Link-disjoint

Node-disjoint

Node-disjoint

Obstacles considered

Yes No No Yes

15


Background

• Vehicle moving similarity [11]– Select neighbor nodes which have similar speeds with

the sender as relay nodes– Vehicle moving similarity is reflected by Vehicle

persistence score (VPS)

16


Background

• Vehicle persistence score (VPS)– VPS table entry <ID, position, road segment, direction,

VPS> [12]– ID: the neighbor’s identifier– position: the GPS coordinate (x, y), which stands for the

neighbor’s position – road segment : where the neighbor is located– direction: the neighbor’s moving direction– VPS: the value used to reflect the neighbor’s stability

17


Background

• VPS maintains– When a node received a HELLO message from a

neighbor, it searched its VPS table– If the neighbor’s ID can be found in the VPS table, the

node increases the neighbor's VPS by 1– If the neighbor’s ID can not be found in the VPS table,

the node adds the neighbor’s information ( ID, position, road segment, direction, and VPS) to the VPS table, and initializes the node’s VPS to 1

18


Background

• An example of VPS table [11]

(a) VPS values are initialized when receiving a HELLO message

(b) VPS values are increased when receiving a HELLO message

19

A

B

CD

E

F

ID VPSABCDE

11111

R A

B

CD

E

F

ID VPSABDEF

22221

R


Design approach - RBMR

• Two stages of the proposed road-based multipath routing (RBMR) – Route discovery stage– Data transfer stage

20


RBMR – Route discovery stage

• How a relay node handles RREQ

21

Start

Is the road segment number of the node recorded in the header

Add the road segment number to the header Broadcast the RREQ

Discard the RREQ

No

End

Are road segment numbers the same with previous received

Dose the node receive the RREQ at first time No

No

Yes

Yes

Yes



• RREQ packet transfer

22

S A

C

B

E

D

F

Steps:1. S sends RREQ to A and C2. C sends RREQ to A3. A discards RREQ which gets from C4. A sends RREQ to B and E5. E sends RREQ to D6. B sends RREQ to F and D7. D discards RREQ which gets from B8. F sends RREQ to D



• Road segment ID recorded in the RREQ header

23

A13

A1

A6

A11

A8

A4

A9

A5

A10

A2

A7

A12

Sender

Receiver

A13,A8,A6 A13,A8,A6,A7

A13,A8

A13,A11 A13,A11,A12

A13,A11,A12,A10

A13,A11,A12,A10,A5

A13,A8,A6,A7,A5

A3

A14 A15

PATH1

PATH2

A13,A8,A3

A13,A8,A3,A1 A13,A8,A3,A1,A2

A13,A8,A3,A1,A2, A5

PATH3



• First, PATH1 is established from sender to receiver

• Second, PATH2 is established

• Third, PATH3 is established

• PATH2 will be discarded at receiver because the road segment A8 has been used

24



• RREP returned PATH1 and PATH3 through the reverse road segment IDs

25A13

A1

A6

A11

A8

A4

A9

A5

A10

A2

A7

A12

Sender

Receiver

A13,A11,A12,A10,A5

A13,A8,A6,A7,A5

A3

A14 A15

PATH1

PATH3



• RBMR will send packets although only PATH1 is established

• PATH3 will be established later, and it will be used if PATH1 is disconnected

26


RBMR – Data transfer stage

• Relay nodes selection– Select relay nodes from the VPS table according to the

data stored in the VPS table– Data used for selection [12]

• road segment: used to choose relay nodes which located in the next road segment of the header

• direction : used to choose relay nodes which moved toward the receiver

• VPS: used to choose a relay node which has the highest score

27


RBMR – Data transfer stage

• Relay node is selected by VPS

28

M N

A

P

E

ID VPS

MAPE

1

3

24

Node N VPS table

D

C

B


Simulation and discussion

• Packet delivery ratio: the number of data packets received at the receiver divided by the number of data packets generated at the sender [11]

• Control overhead: when transferring a packet, how many control packets (including RREQ, RREP, RRER) need to send [11]

• End-to-end delay: the time taken for a packet to be transmitted (including RREQ, RREP) from sender to receiver [8]

29



• Simulation settings [13][14]

30

Parameter Value Transmission range 376 m MAC Protocol IEEE 802.11pNetwork area 1000 m x 1000 m Simulation time 600 s Number of nodes 30, 40, 50, 60, 70 Connection type CBR Packet size 512bytes Mobility model VanetMobiSim Sender and receiver pairs 10Packet sending rate 10 packet/secMax. traffic lights 10Min. Speed 8 m/s Max. Speed 17 m/s Max. acceleration 0.6 m/s2

Normal deceleration 0.5 m/s2



• Delivery ratio under different numbers of nodes

31



32

• Control overhead under different numbers of nodes



• End-to-end delay under different numbers of nodes

33


Conclusion and Future Work

• We propose a road-based multipath routing (RBMR) protocol for Urban VANETs

• The proposed RBMR improves the delivery ratio by 9% 6% , and 15%, control overhead by 30%, 25%, and 19%, and end-to-end delay by 28%, 11%, and 7% compared with AOMDV, NDMR, and CLA, respectively

• Simulation results show that the proposed RBMR

performs well on packet transferring in city environments than road-based single path and node-centric multipath routing protocols.

34


Conclusion and Future Work

• Create over two node-disjoint paths and select the most reliable path to transfer packets

35


References

[1] C. E. Perkins and E. M. Royer, “Ad hoc on-demand distance vector routing,” in Proc. 2nd IEEE Workshop Mobile Comput. Syst. Appl., New Orleans, LA, Feb. 1999, pp. 90–100.

[2] D. B. Johnson and D. A. Maltz, “Dynamic source routing in ad hoc wireless networks,” in Proc. Mobile Comput., vol. 353, no. 5, pp. 153–161, 1996.

[3] Josiane Nzouonta, Neeraj Rajgure, Guiling (Grace) Wang, “VANET Routing on City Roads Using Real-Time Vehicular Traffic Information,” in Proc. IEEE Transactions on Vehicular Technology, pp. 3609-3626, 2009.

[4] P. Bose, P. Morin, I. Stojmenovic, and J. Urrutia, “Routing with guaranteed delivery in ad hoc wireless networks,” in Proc. ACM Wirel. Netw., vol. 7, no. 6, pp. 609–616, Nov. 2001.

[5] F. Kuhn, R. Wattenhofer, Y. Zhang, and A. Zollinger, “Geometric ad hoc routing: Of theory and practice,” in Proc. 22nd Annu. Symp. Principles Distrib. Comput., Boston, MA, Jul. 2003, pp. 63–72.

[6] Xuefei Li; Cuthbert L, ”On-demand Node-Disjoint Multipath Routing in Wireless Ad hoc Networks,” in Proc. IEEE International Conference on Local Computer Networks, pp 419-420, 2004.

[7] Xiaoxia Huang, Yuguang Fang,“ Performance Study of Node-Disjoint Multipath Routing in Vehicular Ad Hoc Networks”, in Proc. IEEE Transactions on Vehicular Technology, pp 1942-1950, 2009.

[8] Y. H. Ho, A. H. Ho, and K. A. Hua, “Routing Protocols for Inter-Vehicular Networks: A Comparative Study in High-Mobility and Large Obstacles Environments, ” Computer Communications Journal - Special Issue on Mobility Protocols for ITS/VANET, 2008.

[9] Mahesh K. Marina, Sami R. Das,”On-demand Multipath Distance Vector Routing in Ad Hoc Networks”, in Proc. Ninth International Conference on Network Protocols, pp 14-23, 2001.

[10]Chang-Woo Ahn, “ A Node-Disjoint Multipath Routing Protocol Based on AODV in Mobile Ad Hoc Networks”, in proc. Seventh International Conference on Information Technology, pp828-833,2010.

36


References

[11] Min Hsuan, Kuochen Wang,” A reliable routing scheme based on vehicle moving similarity for VANETs”, in Proc. IEEE Region 10 Conference on TENCON, pp 426-430,2011.

[12] H.-F. Ho, K.C. Wang, Y.-L. Hsieh, “Resilient Video Streaming for Urban VANETs,” in Proceedings of the Seventh Workshop on Wireless Ad Hoc and Sensor Networks, 2011.

[13] “The network simulator (NS2),” [Online]. Available: http://www.isi.edu/nsnam/ns/.[14] M. Fiore, J. Härri, F. Filali, and C. Bonnet, “Vehicular mobility simulation for VANETs,” in Proc. 40th Annual Simulation

Symp., Mar. 2007, pp. 301-307.

37

Documents

Road-Based Multipath Routing in Urban VANETs 都會區車輛隨意網路之多重路徑繞徑技術