Road-Based Multipath Routing in Urban VANETs. 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. Outline. Introduction Related work Background Design approach Simulation and discussion Conclusion References. Introduction. - PowerPoint PPT Presentation
Resilience in Live Peer-to-Peer Streaming
Road-Based Multipath Routing in Urban VANETs
1Copyright 2012, MBL@CS.NCTU OutlineIntroductionRelated workBackgroundDesign approachSimulation and discussionConclusion References
2Copyright 2012, MBL@CS.NCTU IntroductionVehicular Ad Hoc Networks (VANETs) consists of mobile nodes, and each node moves arbitrarily and communicates with others by multiple wireless links.
Wireless links would be broken frequently because of high mobility in VANET.
In urban VANET , each vehicle moves in constrained areas independently.
3Copyright 2012, MBL@CS.NCTU IntroductionAd-hoc on-demand distance vector(AODV)  and dynamic source routing(DSR)  are two most widely studied on-demand ad hoc routing protocol.
The traditional node-centric view of the route leads to frequent broken routes in the presence of VANETs high mobility.4Copyright 2012, MBL@CS.NCTU Introduction5Node-centric problem .
Copyright 2012, MBL@CS.NCTU IntroductionOne alternative approach is offered by geographical routing protocols, e.g., greedyfacegreedy (GFG) , greedy other adaptive face routing (GOAFR) .
It can not always find the route to destination.6Copyright 2012, MBL@CS.NCTU IntroductionGeographical routing problem .
Copyright 2012, MBL@CS.NCTU Introduction proposed road-based VANET routing protocol that leverage real-time vehicular traffic information to create path.
There are many single path routings, which need to create a new route when a path breaks.
8Copyright 2012, MBL@CS.NCTU IntroductionMultipath routing creates many paths from sender to receiver.
If one route disconnects, sender can choose other routes to transfer.
 has proofed multiple path can improve the packet delivery ratio if there is no interference.
9Copyright 2012, MBL@CS.NCTU IntroductionMultiple path can classify two types : node-disjoint and link-disjoint .
10Copyright 2012, MBL@CS.NCTU Introduction(a) Node-disjoint and (b) link-disjoint.
Copyright 2012, MBL@CS.NCTU Introduction has proofed node-disjoint is better than link-disjoint on packet delivery ratio.12Copyright 2012, MBL@CS.NCTU IntroductionWe propose a road-based multipath routing(RBMR) which is node-disjoint.Improve the reliability of routing pathsMaintain a modified vehicle persistence score (VPS)  to determine the stability of a node
13Copyright 2012, MBL@CS.NCTU Related workOn-demand multipath distance vector routing (AOMDV)  creates several paths from source to destination, and packets are sent after paths established.
14Copyright 2012, MBL@CS.NCTU Related workAOMDV has a route cutoff problem, which means some reverse paths would be ignored .15
Copyright 2012, MBL@CS.NCTU Related work tries to solve route cutoff problem, But it transfers packets after all paths are created.16Copyright 2012, MBL@CS.NCTU Related work is a node-disjoint multipath routing.
It sends packets after creating one path. but it is node-centric routing protocol, so the route is easy to disconnect than road-based routing protocol.
17Copyright 2012, MBL@CS.NCTU Related work Routing method AOMDV NDMR RBMR (proposed) Path counts 2 2 2 Node-centric or Road-based Node-centric Node-centric Road-based Node-disjoint or Link-disjoint Link-disjoint Node-disjoint Node-disjoint Obstacles considered No No Yes18Copyright 2012, MBL@CS.NCTU Background Modified vehicle persistence score (VPS)VPS tableVPS table entry ID: the neighbors identifierposition: the GPS coordinate (x, y), which stands for the neighbors position road segment : the neighbor is locateddirection: the neighbors moving directionVPS: the value used to select relay node
19Copyright 2012, MBL@CS.NCTU BackgroundVPS maintainsWhen node received a HELLO message , it searched its VPS table.If the neighbors ID can be found in the VPS table, the node increases neighbor's VPS by 1.If identifier can not be found in the VPS table, the node adds the neighbors information to the VPS table, and initializes the nodes VPS to 1.
20Copyright 2012, MBL@CS.NCTU Background An example of VPS table (a) VPS values are initialized when receiving a HELLO message(b) VPS values are increased when receiving a HELLO message21
Copyright 2012, MBL@CS.NCTU Design approach - RBMRTwo stages of the proposed road-based multipath routing (RBMR) Route discovery stageData transfer stage
22Copyright 2012, MBL@CS.NCTU RBMR Route discovery stageHow Relay node handles RREQ
Copyright 2012, MBL@CS.NCTU RBMR Route discovery stageRREQ packet transfers.24
Copyright 2012, MBL@CS.NCTU RBMR Route discovery stageRoad segment ID recorded in the RREQ header.25
Copyright 2012, MBL@CS.NCTU RBMR Route discovery stageRREP returned through the reverse road segment IDs.
Copyright 2012, MBL@CS.NCTU RBMR Data transfer stageRelay nodes selectionSelect relay nodes from the VPS table according to the data stored in the VPS tableData used for selection 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 relay node which has the highest.
27Copyright 2012, MBL@CS.NCTU RBMR Data transfer stageRelay node is selected by VPS.
Copyright 2012, MBL@CS.NCTU Simulation and discussionPacket delivery ratio: the number of data packets received at receiver divided by the number of data packets generated at sender.29Copyright 2012, MBL@CS.NCTU Simulation and discussion Routing overhead: when transferring a packet, how many control messages need to send.
30Copyright 2012, MBL@CS.NCTU Simulation and discussionSimulation settings for NS2 31Parameter Value Transmission range 376 m MAC Protocol IEEE 802.11pNetwork area 1000 m x 1000 m Simulation time 600 s Number of vehicles 30, 40, 50, 60, 70 Connection type CBR Packet size 512bytes Mobility model VanetMobiSim Sender and receiver pairs4Copyright 2012, MBL@CS.NCTU Simulation and discussionSimulation settings for VanetMobiSim 
32Parameter Value Simulation Time600sMax. traffic lights 10 Terrain Dimension1000m x 1000mNodes (vehicles) 30, 40, 50, 60, 70 Min. Speed 8 m/s Max. Speed 17 m/s Max. acceleration 0.6 m/s2Normal deceleration 0.5 m/s2Copyright 2012, MBL@CS.NCTU Simulation and discussionDelivery ratio under different numbers of nodes33
Copyright 2012, MBL@CS.NCTU 33Simulation and discussion34Routing overhead under different numbers of nodes
Copyright 2012, MBL@CS.NCTU ConclusionWe propose road-based multipath routing for Urban VANETs.
The proposed RBMR improves the delivery ratio by 9% and control overhead by 30% compared with AOMDV and NDMR. Simulation results show that the proposed RBMR performs well in city environments.
35Copyright 2012, MBL@CS.NCTU ReferencesC. 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. 90100. D. B. Johnson and D. A. Maltz, Dynamic source routing in ad hoc wireless networks, Mobile Comput., vol. 353, no. 5, pp. 153161, 1996. Josiane Nzouonta, Neeraj Rajgure, Guiling (Grace) Wang, VANET Routing on City Roads Using Real-Time Vehicular Traffic Information, IEEE Transactions on Vehicular Technology, pp. 3609-3626, 2009.P. Bose, P. Morin, I. Stojmenovic, and J. Urrutia, Routing with guaranteed delivery in ad hoc wireless networks, ACM Wirel. Netw., vol. 7, no. 6, pp. 609616, Nov. 2001.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. 6372.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.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.
36Copyright 2012, MBL@CS.NCTU References37 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.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.Bo Xue, Pinyi Ren, Shuangcheng Yan ,Link Optimization Ad-hoc On-Demand Multipath Distance Vector Routing for Mobile Ad-hoc Networks, in Proc. International Conference on Wireless Communications, Networking and Mobile Computing, pp 1-6,2009.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. 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.The network simulator (NS2), [Online]. Available: http://www.isi.edu/nsnam/ns/. M. Fiore, J. Hrri, F. Filali, and C. Bonnet, Vehicular mobility simulation for VANETs, in Proc. 40th Annual Simulation Symp., Mar. 2007, pp. 301-307.
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