1Road Side Unit Assisted Stochastic multi-hopBroadcast Scheme for Instant Emergency
Message Propagation
Xing Fan*, Bo Yang*, Ryo Yamamoto**, Yoshiaki Tanaka*,****Global Information and Telecommunication Institute, Waseda University
1-3-10 Nishi-Waseda, Shinjuku-ku, Tokyo, 169-0051 Japan** Graduate School of Information Systems, The University of Electro-Communications
1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan*** Research Institute for Science and Engineering, Waseda University
17 Kikuicho, Shinjuku-ku, Tokyo, 162-0044 Japan
fan.xing@asagi.waseda.jp, yangbo_youhaku@ruri.waseda.jp, ryo_yamamoto@is.uec.ac.jp, ytanaka@waseda.jp

Abstract— VANET (Vehicular ad hoc Network) is a special kind of ad hoc wireless network where every single node is a vehicle
moving in a relatively high velocity, which leads to exclusive challenges like rapid changing topologies, safety and privacy concerns. In
this specific network, broadcasts tend to be carrying important messages such as car accident notification, disaster alert or extreme
traffic condition. Thus the propagation of broadcasted emergency messages could be critical to save human lives and property. Manyresearchers have proposed routing or broadcast protocols to solve this problem in VANET. With consideration of the other commonissues. The objective of this paper is to propose a broadcast scheme in VANET that is not likely to cause broadcast storm problem
with a reasonable delay and high delivery rate. Since VANET is an attack-prone network and any kind of malicious behavior inVANET might cause serious loss or even death in reality, we should also refrain from using beacons to exchange privacy-sensitive
information in V2V (Vehicle to Vehicle). In this paper, a multi-hop broadcast scheme that makes use of RSU and V2I (Vehicle toInfrastructure) communication is proposed. The simulation result shows that the proposed scheme outperforms static stochastic
broadcast scheme in terms of delivery rate. Comparing to flooding, we offer a better delay and less network usage.
Keyword— VANET, Broadcast, Percolation, Stochastic, Wireless
Xing Fan was born in Shanxi, China on June 30th. Xing Fan earned bachelor of engineering in Beijing University of Technology in July
2012. Xing Fan is a master student majored in ad hoc network at Waseda University, Japan while presenting this paper.

Bo Yang received his B. E. degree in computer science and technology from Xi Dian University, Xi’an, China, in 2009. He received hissecond M.E. degree in Information Communication from Waseda University, Tokyo, Japan, in 2012. Currently, he is working toward thePh. D degree in the Global Information and Telecommunication Studies, Waseda University, Tokyo, Japan. He won the ICACT best paper
award in Feb. 2012.

Ryo Yamamoto received his B.E. and M.E. degree in electronic information systems from Shibaura Institute of Technology, Tokyo, Japan,in 2007 and 2009. He received D.S. in global telecommunication studies from Waseda University, Tokyo, Japan, in 2013. He was aresearch associate at Graduate School of Global Information and Telecommunication Studies, Waseda University, from 2010 to 2014, andhas been engaged in researching in wireless communication networks. He is presently an assistant professor at Graduate School ofInformation Systems, The University of Electro-Communications. He received the IEICE young researcher's award in 2010, the IEICE
Network System Research Award in 2014. His current research interests are mobile ad hoc networks and cross-layered protocols.

2Yoshiaki Tanaka received the B.E., M.E., and D.E. degrees in electrical engineering from the University of Tokyo, Tokyo, Japan, in1974, 1976, and 1979, respectively. He became a staff at Department of Electrical Engineering, the University of Tokyo, in 1979, and has
been engaged in teaching and researching in the fields of telecommunication networks, switching systems, and network security. He was aguest professor at Department of Communication Systems, Lund Institute of Technology, Sweden, from 1986 to 1987. He was also avisiting researcher at Institute for Posts and Telecommunications Policy, from 1988 to 1991, and at Institute for Monetary and Economic
Studies, Bank of Japan, from 1994 to 1996. He is presently a professor at Department of Communications and Computer Engineering,
Waseda University, and a visiting professor at National Institute of Informatics. He received the IEEE Outstanding Student Award in 1977,the Niwa Memorial Prize in 1980, the IEICE Achievement Award in 1980, the Okawa Publication Prize in 1994, the TAF Telecom System
Technology Award in 1995 and in 2006, the IEICE Information Network Research Award in 1996, in 2001, in 2004, and in 2006, the IEICE
Communications Society Activity Testimonial in 1997 and in 1998, the IEICE Switching System Research Award in 2001, the IEICE Best
Paper Award in 2005, the IEICE Network System Research Award in 2006, in 2008, and in 2011, the IEICE Communications Society Activity Award in 2008,
the Commendation by Minister for Internal Affairs and Communications in 2009, the APNOMS Best Paper Award in 2009 and in 2012, and the IEICEDistinguished Achievement and Contributions Award in 2013. He is a Fellow of IEICE.