Take a look at the new version of this page: [ beta version ]. Tell us what you think.

ABSTRACT

Safety message exchange is the most prevalent part of inter-vehicular communications which is crucial for enhancing safety and efficiency in transportation networks. Moreover, since the dissemination of safety messages directly influences our lives, their reliable delivery is of great importance. Most packet collisions in VANETs occur due to hidden nodes. In unicast communications a two-way handshaking is performed prior to the actual transmission in order to alleviate the hidden node problem. However, this procedure congests the network with a lot of overhead in case of broadcast, which is the dominant mode of communication in VANETs. Hence, in this paper we propose an alternative solution, based on retransmissions, to ensure the reliable delivery of safety messages. We argue that the specific characteristics inherent in VANETs, such as the limited density of vehicles, anticipated bandwidth and the tolerable delay, allow us to deploy a retransmission strategy. Furthermore, We prove that our proposed scheme establishes fair channel access for the consecutive retransmission opportunities of contending neighbors. Simulation results confirm that our heuristic method dramatically improves the probability of reception of safety messages regarding conventional methods.

REFERENCES

• 1: BTS, "National transportation statistics 2006." http://www.bts.gov/publications/national_tran sportation_statistics/2006/, 2006.
• 2: Marc Torrent-Moreno , Paolo Santi , Hannes Hartenstein, Fair sharing of bandwidth in VANETs, Proceedings of the 2nd ACM international workshop on Vehicular ad hoc networks, September 02-02, 2005, Cologne, Germany [doi>10.1145/1080754.1080762]
• 3: D. Jiang, V. Taliwal, A. Meier, and W. Holfelder, "Design of 5.9 Ghz DSRC-based vehicular safety communication", IEEE Wireless Communications, vol. 13, October 2006.
• 4: Qing Xu , Tony Mak , Jeff Ko , Raja Sengupta, Vehicle-to-vehicle safety messaging in DSRC, Proceedings of the 1st ACM international workshop on Vehicular ad hoc networks, October 01-01, 2004, Philadelphia, PA, USA [doi>10.1145/1023875.1023879]
• 5: H. Pishro-Nik, A. Ganz, and D. Ni, "The capacity of vehicular ad hoc networks", in Proceedings of 45th Annual Allerton Conference on Communications, Control and computing.
• 6: M. Nekoui, A. Eslami, and H. Pishro-Nik, "Scaling laws for distance limited communications in vehicular ad hoc networks", in Proceedings of IEEE International Conference on Communications (ICC 2008), May 2008.
• 7: M. Nekoui, A. Eslami, and H. Pishro-Nik, "The capacity of vehicular ad hoc networks with infrastructure", in Proceedings of the 6th Intl. Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (Wiopt 2008), April 2008.
• 8: J. Zhu and S. Roy, "MAC for dedicated short range communications in intelligent transport system", IEEE Communications Magazine, vol. 41, December 2003.
• 9: Maen M. Artimy , William Robertson , William J. Phillips, Assignment of dynamic transmission range based on estimation of vehicle density, Proceedings of the 2nd ACM international workshop on Vehicular ad hoc networks, September 02-02, 2005, Cologne, Germany [doi>10.1145/1080754.1080761]

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design

General Terms:
Algorithms, Performance, Theory

Keywords:
dedicated short range communications (DSRC), inter-vehicle communications (IVC), vehicular ad hoc networks (VANETs)