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Road-Based Multipath Routing With Resilient Video Streaming for 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 Background Related work Design approach References. Introduction.
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Road-Based Multipath Routing With Resilient Video Streaming for 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 • Background • Related work • Design approach • References
Introduction • It is commonly acknowledged that Vehicular Ad Hoc Networks (VANETs) are unsuited to support multimedia traffic. • In urban VANET , each vehicle moves in constrained areas independently.
Introduction Wireless links would be broken frequently because of high mobility in VANET. Due to the error-prone characteristic of wireless communication, routing packets over multiple hops results in packet loss and causes poor quality of reconstructed video at the receiver
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 protocol The traditional node-centric view of the route leads to frequent broken routes in the presence of VANETs’ high mobility as illustrated in Figure 1 [3]
Introduction One alternative approach is offered by geographical routing protocols, e.g., greedy–face–greedy (GFG) [4], greedy other adaptive face routing (GOAFR) [5] It can not always find the route to destination as illustrated in Figure 2
Introduction There are many single path routings, which need new route discovery whenever a path breaks [6] has proofed multiple path can improve the packet delivery ratio if there is no interference.
Introduction PA andPB arepacket delivery ratio without interference for each single path Psin: Single path routing delivery ratio Pmulti : Multiple path routing delivery ratio
Introduction Psin=Max{PA,PB} (1) Pmulti=1-(1-PA)(1-PB)=PA+PB-PAPB (2) PA <1 and PB <1 , PA*PB < Min{PA,PB} (3) Pmulti ≥ Max{PA,PB} ≥ Psin (4)
Introduction • We propose a road-based multipath routing with resilient video streaming scheme that integrates flexible macroblock ordering (FMO) and multiple description coding (MDC) • Improve video streaming quality • Recover lost packets with error resilience via FMO and MDC • Improve the reliability of routing paths • Maintain a modified vehicle persistence score (VPS) [8] to determine the stability of a node
Background • Vehicle persistence score (VPS) • VPS table • VPS table entry<ID, position, block, direction, VPS> • ID: the neighbor’s identifier • position: the GPS coordinate (x, y), which stands for the neighbor’s position • block: the neighbor is located • direction: the neighbor’s moving direction • VPS: the value used to select relay node
Background • VPS maintains • When vehicle received a HELLO message , it searched its VPS table • If the neighbor’s ID can be found in the VPS table, the vehicle increasesneighbor's VPS by 1. • If identifier can not be found in the VPS table, the vehicle adds the neighbor’s information to the VPS table, and initializes the neighbor’s VPS to 1.
Background (a) VPS values are initialized when receiving a HELLO message (b) VPS values are increased when receiving a HELLO message An example of VPS table
Background • Flexible Macroblock Ordering (FMO) [9] • One of error resilience techniques defined by the H.264/AVC specifications • An image is divided into slice groups, and each slice group can be divided into several slices, consisting of a sequence of macroblocks that belong to the same slice group • The power of FMO depends on how the macroblocks are ordered
Background • FMO type[9]
Background • Multiple Description Coding (MDC)[10] • The basic principle of MDC is that the encoder, given an input signal (image, audio, video, etc.), is able to produce a set of descriptions • As any further description is received, the quality of the reconstruction increases
Design approach - RMRVS • Four phases of the proposed road-based multipath routing with resilient video streaming(RMRVS) scheme • Video encoding phase • Route discovery phase • Data forwarding phase • Video decoding phase
RMRVS – Video encoding phase • Video encoding phase • Before a sender starts transmitting to a receiver, it encodes the row video stream with FMO type 1 and classifies two descriptions by MDC, splitting the video streaming into two descriptionsfor error resilience at the receiver
RMRVS – Route discovery phase Block ID recorded in the RREQ header
RMRVS – Route discovery phase RREP is sent by the reverse block ID
RMRVS – Data forwarding phase • Relay nodes selection • Select relay nodes from the VPS table according to the data stored in the VPS table • Data used for selection • block: used to choose a relay node which located in the next block in the header • direction: used to choose a relay node with the moving direction that will move toward the receiver • VPS: a node with the highest VPS value will be selected
RMRVS – Video decoding phase • Video decoding phase • After a receiver receives all packets transmitting from a sender, it decodes and creates a reconstructed video stream
References • C. E. Perkins and E. M. Royer, “Ad hoc on-demand distance vectorrouting,” in Proc. 2nd IEEE Workshop Mobile Comput. Syst. Appl.,New Orleans, LA, Feb. 1999, pp. 90–100. • D. B. Johnson and D. A. Maltz, “Dynamic source routing in ad hoc wireless networks,” Mobile Comput., vol. 353, no. 5, pp. 153–161, 1996. • Nzouonta, J.,Rajgure, N.,GuilingWang,Borcea, C.,“VANET Routing on City Roads Using Real-Time Vehicular Traffic Information” , ,” in Proc. IEEE Vehicular Technology , 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. 609–616, 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. 63–72. • XiaoxiaHuang,Yuguang Fang ,” Performance Study of Node-Disjoint Multipath Routing in Vehicular Ad Hoc Networks” , in Proc. IEEE Vehicular Technology , 2009 • Bo Xue,PinyiRen,Shuangcheng Yan, “Link Optimization Ad-hoc On-Demand MultipathDistance Vector Routing for Mobile Ad-hoc Networks” , in Proc. IEEE Wireless Communications , 2009 • M.H. Wei, K.C. Wang, and I.L. Hsieh “A reliable routing scheme based on vehicle moving similarity for VANETs,” in Proc. IEEE TENCON, 2011. • S. Wenger, “H2.46/AVC over IP,” IEEE Trans. on Circuits and Syst. for Video Technol., vol. 13, no. 7, pp. 645-656, 2003.
References Greco, C.,Petrazzuoli, G.,Cagnazzo, M., Pesquet-Popescu, B , “An MDC-based video streaming architecture for mobile networks”, in Proc. IEEE MMSP , 2009 .