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Issue No.08 - August (2011 vol.22)
pp: 1258-1266
Hongzi Zhu , Shanghai Jiao Tong University and Shanghai Key Lab of Scalable Computing and Systems, Shanghai
Minglu Li , Shanghai Jiao Tong University and Shanghai Key Lab of Scalable Computing and Systems, Shanghai
Luoyi Fu , Shanghai Jiao Tong University, Shanghai
Guangtao Xue , Shanghai Jiao Tong University and Shanghai Key Lab of Scalable Computing and Systems, Shanghai
Yanmin Zhu , Shanghai Jiao Tong University and Shanghai Key Lab of Scalable Computing and Systems, Shanghai
Lionel M. Ni , The Hong Kong University of Science and Technology, Hong Kong and Shanghai Key Lab of Scalable Computing and Systems, Shanghai
Intercontact time between moving vehicles is one of the key metrics in vehicular ad hoc networks (VANETs) and central to forwarding algorithms and the end-to-end delay. Due to prohibitive costs, little work has conducted experimental study on intercontact time in urban vehicular environments. In this paper, we carry out an extensive experiment involving thousands of operational taxies in Shanghai city. Studying the taxi trace data on the frequency and duration of transfer opportunities between taxies, we observe that the tail distribution of the intercontact time, that is, the time gap separating two contacts of the same pair of taxies, exhibits an exponential decay, over a large range of timescale. This observation is in sharp contrast to recent empirical data studies based on human mobility, in which the distribution of the intercontact time obeys a power law. By analyzing a simplified mobility model that captures the effect of hot areas in the city, we rigorously prove that common traffic influxes, where large volume of traffic converges, play a major role in generating the exponential tail of the intercontact time. Our results thus provide fundamental guidelines on design of new vehicular mobility models in urban scenarios, new data forwarding protocols and their performance analysis.
Vehicular ad hoc networks, intercontact time, exponential tail, mobility model, traffic influx, empirical data analysis.
Hongzi Zhu, Minglu Li, Luoyi Fu, Guangtao Xue, Yanmin Zhu, Lionel M. Ni, "Impact of Traffic Influxes: Revealing Exponential Intercontact Time in Urban VANETs", IEEE Transactions on Parallel & Distributed Systems, vol.22, no. 8, pp. 1258-1266, August 2011, doi:10.1109/TPDS.2010.176
[1] A. Chaintreau, P. Hui, J. Crowcroft, C. Diot, R. Gass, and J. Scott, "Impact of Human Mobility on the Design of Opportunistic Forwarding Algorithms," Proc. IEEE INFOCOM, 2006.
[2] A. Bar-Noy, I. Kessler, and M. Sidi, "Mobile Users: To Update or Not to Update?," Proc. IEEE INFOCOM, 1994.
[3] A.E. Gamal, J. Mammen, B. Prabhakar, and D. Shah, "Throughput-delay Trade-Off in Wireless Networks," Proc. IEEE INFOCOM, 2004.
[4] G. Sharma and R. Mazumdar, "Scaling Laws for Capacity and Delay in Wireless Ad Hoc Networks with Random Mobility," Proc. IEEE Int'l. Conf. Comm. (ICC), 2004.
[5] D. Johnson and D. Maltz, "Dynamic Source Routing in Ad Hoc Wireless Networks," Mobile Computing, T. Imelinsky and H. Korth, eds., pp. 153-181, Kluwer Academic Publishers, 1996.
[6] J. Broch, D. Maltz, D. Johnson, Y. Hu, and J. Jetcheva, "Multi-Hop Wireless Ad Hoc Network Routing Protocols," Proc. ACM/IEEE MOBICOM, 1998.
[7] C. Chiang and M. Gerla, "On-Demand Multicast in Mobile Wireless Networks," Proc. IEEE Int'l Conf. Network Protocols (ICNP), 1998.
[8] P. Johansson, T. Larsson, N. Hedman, B. Mielczarek, and M. Degermark, "Routing Protocols for Mobile Ad-Hoc Networks—A Comparative Performance Analysis," Proc. ACM/IEEE MOBICOM, 1999.
[9] E. Royer, P.M. Melliar-Smith, and L. Moser, "An Analysis of the Optimum Node Density for Ad Hoc Mobile Networks," Proc. IEEE Int'l Conf. Comm. (ICC), 2001.
[10] R. Groenevelt, P. Nain, and G. Koole, "Message Delay in MANET," Proc. ACM SIGMETRICS, 2004.
[11] G. Sharma and R.R. Mazumdar, "Delay and Capacity Trade-Off in Wireless Ad Hoc Networks with Random Mobility," ACM/Kluwer J. Mobile Networks and Applications, 2004.
[12] H. Cai and D.Y. Eun, "Crossing over the Bounded Domain: From Exponential to Power-Law Inter-Meeting Time in MANET," Proc. ACM/IEEE MOBICOM, 2007.
[13] T. Henderson, D. Kotz, and I. Abyzov, "The Changing Usage of a Mature Campus-Wide Wireless Network," Proc. ACM Mobicom, 2004.
[14] P. Hui, A. Chaintreau, J. Scott, R. Gass, J. Crowcroft, and C. Diot, "Pocket Switched Networks and the Consequences of Human Mobility in Conference Environments," Proc. ACM SIGCOMM First Workshop Delay Tolerant Networking and Related Topics (WDTN '05), 2005.
[15] M. McNett and G.M. Voelker, "Access and Mobility of Wireless PDA User," technical report, Dept. of Computer Science and Eng., UC San Diego, 2004.
[16] X. Zhang, J. Kurose, B.N. Levine, D. Towsley, and H. Zhang, "Study of a Bus-Based Disruption-Tolerant Network: Mobility Modeling and Impact on Routing," Proc. ACM/IEEE MOBICOM, 2007.
[17] A. Balasubramanian, B.N. Levine, and A. Venkataramani, "DTN Routing as a Resource Allocation Problem," Proc. ACM SIGCOMM, 2007.
[18] M. Li, M. Wu, Y. Li, J. Cao, L. Peng, Q. Deng, X. Lin, C. Jiang, W. Tong, Y. Gui, A. Zhou, X. Wu, and S. Jiang, "ShanghaiGrid: An Information Service Grid," Concurrency and Computation: Practice & Experience, vol. 18, no. 1, pp. 111-135, John Wiley and Sons Ltd., 2006.
[19] Y. Gunter and H.P. Großmann, "Usage of Wireless LAN for Inter-Vehicle Communication," Proc. Eighth Int'l IEEE Conf. Intelligent Transportation Systems, 2005.
[20] R. Lu, X. Lin, and X. Shen, "SPRING: A Social-Based Privacy-Preserving Packet Forwarding Protocol for Vehicular Delay Tolerant Networks," Proc. IEEE INFOCOM, 2010.
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