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Issue No.06 - June (2011 vol.10)

pp: 868-880

D. Manjunath , Indian Institute of Technology Bombay, Mumbai

Karen Sollins , Masachusetts Institute of Technology, Cambridge

Nishanth Sastry , University of Cambridge, Cambridge

DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2010.225

ABSTRACT

Pocket Switched Networks take advantage of social contacts to opportunistically create data paths over time. This work employs empirical traces to examine the effect of the human contact process on data delivery in such networks. The contact occurrence distribution is found to be highly uneven: contacts between a few node pairs occur too frequently, leading to inadequate mixing in the network, while the majority of contacts occur rarely, but are essential for global connectivity. This distribution of contacts leads to a significant variation in the fraction of node pairs that can be connected over time windows of similar duration. Good time windows tend to have a large clique of nodes that can all reach each other. It is shown that the clustering coefficient of the contact graph over a time window is a good predictor of achievable connectivity. We then examine all successful paths found by flooding and show that though delivery times vary widely, randomly sampling a small number of paths between each source and destination is sufficient to yield a delivery time distribution close to that of flooding over all paths. This result suggests that the rate at which the network can deliver data is remarkably robust to path failures.

INDEX TERMS

Pocket Switched Networks, human mobility networks, flooding, statistical properties, path failure tolerance.

CITATION

D. Manjunath, Karen Sollins, Nishanth Sastry, "Data Delivery Properties of Human Contact Networks",

*IEEE Transactions on Mobile Computing*, vol.10, no. 6, pp. 868-880, June 2011, doi:10.1109/TMC.2010.225REFERENCES

- [1] P. Hui et al., "Pocket Switched Networks and the Consequences of Human Mobility in Conference Environments,"
Proc. ACM SIGCOMM First Workshop Delay Tolerant Networking and Related Topics, 2005.- [2] M. Grossglauser and D.N.C. Tse, "Mobility Increases the Capacity of Ad Hoc Wireless Networks,"
IEEE/ACM Trans. Networks, vol. 10, no. 4, pp. 477-486, Aug. 2002.- [3] L. McNamara, C. Mascolo, and L. Capra, "Media Sharing Based on Colocation Prediction in Urban Transport,"
Proc. ACM MobiCom, 2008.- [4] J. Travers and S. Milgram, "An Experimental Study of the Small World Problem,"
Sociometry, http://www.jstor.org/stable2786545, vol. 32, no. 4, pp. 425-443, 1969,- [5] R.I.M. Dunbar, "Co-Evolution of Neocortex Size, Group Size and Language in Humans,"
Behavioral and Brain Sciences, vol. 16, pp. 681-735, 1993.- [6] University of California San Diego, "Wireless Topology Discovery Project," http://sysnet. ucsd.edu/wtdwtd.html, 2004.
- [7] N. Eagle and A.S. Pentland, "CRAWDAD Data Set Mit/Reality (v. 2005-07-01)," http://crawdad.cs.dartmouth.edu/mitreality , 2010.
- [8] E. Yoneki, P. Hui, and J. Crowcroft, "Visualizing Community Detection in Opportunistic Networks,"
Proc. Second ACM Workshop Challenged Networks (CHANTS '07), pp. 93-96, 2007.- [9] D.J. Watts and S.H. Strogatz, "Collective Dynamics of 'Small-World' Networks,"
Nature, vol. 393, no. 6684, pp. 440-442, June 1998.- [10] Y.J. Zhao, R. Govindan, and D. Estrin, "Computing Aggregates for Monitoring Wireless Sensor Networks,"
Proc. First IEEE Int'l Workshop Sensor Network Protocols and Applications (SNPA '03), 2003.- [11] T. Small and Z.J. Haas, "The Shared Wireless Infostation Model: A New Ad Hoc Networking Paradigm (or Where There Is a Whale, There Is a Way),"
Proc. ACM MobiHoc, 2003.- [12] X. Zhang, G. Neglia, J. Kurose, and D. Towsley, "Performance Modeling of Epidemic Routing,"
Computer Networks, vol. 51, no. 10, pp. 2867-2891, 2007.- [13] T. Karagiannis, J.-Y. Le Boudec, and M. Vojnovic, "Power Law and Exponential Decay of Inter Contact Times between Mobile Devices,"
Proc. ACM MobiCom, 2007.- [14] A. Chaintreau et al., "Impact of Human Mobility on Opportunistic Forwarding Algorithms,"
IEEE Trans. Mobile Computing, vol. 6, no. 6, pp. 606-620, June 2007.- [15] M.T. Boswell and G.P. Patil, "Chance Mechanisms Generating the Negative Binomial Distribution,"
Random Counts for Scientific Work, vol. 1, pp. 3-22, Pennsylvania State Univ. Press, 1970.- [16] M.S. Handcock and J.H. Jones, "Interval Estimates for Epidemic Thresholds in Two-Sex Network Models,"
Theoretical Population Biology, vol. 70, no. 2, pp. 125-134, 2006.- [17] K. Fall, "A Delay-Tolerant Network Architecture for Challenged Internets,"
Proc. SIGCOMM, 2003.- [18] S. Jain, K. Fall, and R. Patra, "Routing in a Delay Tolerant Network,"
SIGCOMM Computer Comm. Rev., vol. 34, no. 4, pp. 145-158, 2004.- [19] A. Balasubramanian, B.N. Levine, and A. Venkataramani, "DTN Routing as a Resource Allocation Problem,"
Proc. SIGCOMM, 2007.- [20] W. Zhao et al., "Capacity Enhancement Using Throwboxes in DTNs,"
Proc. IEEE Int'l Conf. Mobile Ad Hoc and Sensor Systems (MASS '06), 2006.- [21] E. Daly and M. Haahr, "Social Network Analysis for Routing in Disconnected Delay-Tolerant Manets,"
Proc. ACM MobiHoc, 2007.- [22] A. Lindgren, A. Doria, and O. Schelen, "Probabilistic Routing in Intermittently Connected Networks,"
Proc. Workshop Service Assurance with Partial and Intermittent Resources (SAPIR '04), 2004.- [23] P. Hui, J. Crowcroft, and E. Yoneki, "Bubble Rap: Social-Based Forwarding in Delay Tolerant Networks,"
Proc. ACM MobiHoc, 2008.- [24] R. Groenevelt, P. Nain, and G. Koole, "The Message Delay in Mobile Ad Hoc Networks,"
Performance Evaluation, vol. 62, nos. 1-4, pp. 210-228, 2005.- [25] J.W. Mickens and B.D. Noble, "Modeling Epidemic Spreading in Mobile Environments,"
Proc. Fourth ACM Workshop Wireless Security (WiSe '05), 2005.- [26] V. Erramilli, A. Chaintreau, M. Crovella, and C. Diot, "Diversity of Forwarding Paths in Pocket Switched Networks,"
Proc. ACM Internet Measurement Conf., Oct. 2007.- [27] T. Spyropoulos, K. Psounis, and C.S. Raghavendra, "Efficient Routing in Intermittently Connected Mobile Networks: The Multiple-Copy Case,"
IEEE/ACM Trans. Network, vol. 16, no. 1, pp. 77-90 , Feb. 2008.- [28] V. Erramilli, M. Crovella, A. Chaintreau, and C. Diot, "Delegation Forwarding,"
Proc. ACM MobiHoc, 2008.- [29] P. Hui, K. Xu, V. Li, J. Crowcroft, V. Latora, and P. Lio, "Selfishness, Altruism and Message Spreading in Mobile Social Networks,"
Proc. First IEEE Int'l Workshop Network Science For Comm. Networks (NetSciCom '09), 2009.- [30] A. Broder, R. Kumar, F. Maghoul, P. Raghavan, S. Rajagopalan, R. Stata, A. Tomkins, and J. Wiener, "Graph Structure in the Web,"
Computer Networks, vol. 33, nos. 1-6, pp. 309-320, 2000.- [31] R. Albert, H. Jeong, and A.-L. Barabàsi, "Error and Attack Tolerance of Complex Networks,"
Nature, vol. 406, pp. 378-382, 2000.- [32] N. Kotz, A. Kemp, and S. Kotz,
Univariate Discrete Distributions, third ed. Wiley, 2005. |