People are the network : experimental design and evaluation of social-based forwarding algorithms

Cooperation binds but also divides human society into communities. Members of the same community interact with each other preferentially. There is structure in human society. Within society and its communities, individuals have varying popularity. Some people are more popular and interact with more people than others; we may call them hubs. I develop methods to extract this kind of social information from experimental traces and use it to choose the next hop forwarders in Pocket Switched Networks (PSNs). I find that by incorporating social information , forwarding efficiency can be significantly improved. For practical reasons, I also develop distributed algorithms for inferring communities. Forwarding in Delay Tolerant Networks (DTNs), or more particularly PSNs, is a challenging problem since human mobility is usually difficult to predict. In this thesis, I aim to tackle this problem using an experimental approach by studying real human mobility. I perform six mobility experiments in different environments. The resultant experimental datasets are valuable for the research community. By analysing the experimental data, I find out that the inter-contact time of humans follows a power-law distribution with coefficient smaller than 1 (over the range of 10 minutes to 1 day). I study the limits of " oblivious " forwarding in the experimental environment and also the impact of the power-law coefficient on message delivery. In order to study social-based forwarding, I develop methods to infer human communities from the data and use these in the study of social-aware forwarding. I propose several social-aware forwarding schemes and evaluate them on different datasets. I find out that by combining community and centrality information, forwarding efficiency can be significantly improved, and I call this scheme BUBBLE forwarding with the analogy that each community is a BUBBLE with big bubbles containing smaller bubbles. For practical deployment of these algorithms, I propose distributed community detection schemes, and also propose methods to approximate node centrality in the system. Besides the forwarding study, I also propose a layerless data-centric architecture for the PSN scenario to address the problem with the status quo in communication (e.g. an infrastructure-dependent and synchronous API), which brings PSN one step closer to real-world deployment. Acknowledgments I would like to thank my supervisor Prof. Jon Crowcroft for endless jolly discussions and beers in the Castle. I would also like to thank Dr Christophe Diot, Dr James Scott and Dr Augustin Chaintreau for their wonderful supervision and help during the first …

[1]  Li Li,et al.  Practical Routing in Delay-Tolerant Networks , 2007, IEEE Trans. Mob. Comput..

[2]  P. Oscar Boykin,et al.  Percolation search in power law networks: making unstructured peer-to-peer networks scalable , 2004, Proceedings. Fourth International Conference on Peer-to-Peer Computing, 2004. Proceedings..

[3]  Gerard Salton,et al.  Automatic Text Processing: The Transformation, Analysis, and Retrieval of Information by Computer , 1989 .

[4]  Kevin R. Fall,et al.  A delay-tolerant network architecture for challenged internets , 2003, SIGCOMM '03.

[5]  Charles E. Perkins,et al.  Ad hoc On-Demand Distance Vector (AODV) Routing , 2001, RFC.

[6]  Walter Willinger,et al.  To Peer or Not to Peer: Modeling the Evolution of the Internet's AS-Level Topology , 2006, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[7]  Krishna P. Gummadi,et al.  Exploiting Social Networks for Internet Search , 2006, HotNets.

[8]  M. Newman.  Analysis of weighted networks. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[9]  Cecilia Mascolo,et al.  A community based mobility model for ad hoc network research , 2006, REALMAN '06.

[10]  Alex Pentland,et al.  Reality mining: sensing complex social systems , 2006, Personal and Ubiquitous Computing.

[11]  S. Milgram,et al.  The Individual In A Social World: Essays and Experiments , 1992 .

[12]  Eyal de Lara,et al.  Haggle: Clean-slate networking for mobile devices , 2007 .

[13]  Zygmunt J. Haas,et al.  The shared wireless infostation model: a new ad hoc networking paradigm (or where there is a whale, there is a way) , 2003, MobiHoc '03.

[14]  P C JonesEvan,et al.  Practical Routing in Delay-Tolerant Networks , 2007 .

[15]  Matthias Grossglauser,et al.  Island Hopping: Efficient Mobility-Assisted Forwarding in Partitioned Networks , 2006, 2006 3rd Annual IEEE Communications Society on Sensor and Ad Hoc Communications and Networks.

[16]  Peter V. Marsden,et al.  Egocentric and sociocentric measures of network centrality , 2002, Soc. Networks.

[17]  Peter R. Winters,et al.  Forecasting Sales by Exponentially Weighted Moving Averages , 1960 .

[18]  James A. Davis,et al.  Wearable computers as packet transport mechanisms in highly-partitioned ad-hoc networks , 2001, Proceedings Fifth International Symposium on Wearable Computers.

[19]  Pan Hui,et al.  Haggle: A networking architecture designed around mobile users , 2006 .

[20]  M E J Newman,et al.  Fast algorithm for detecting community structure in networks. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[21]  Marvin Theimer,et al.  Managing update conflicts in Bayou, a weakly connected replicated storage system , 1995, SOSP.

[22]  V. Latora,et al.  Centrality measures in spatial networks of urban streets. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.

[23]  Robert Tappan Morris,et al.  Pastwatch: A Distributed Version Control System , 2006, NSDI.

[24]  Pan Hui,et al.  How Small Labels Create Big Improvements , 2006, Fifth Annual IEEE International Conference on Pervasive Computing and Communications Workshops (PerComW'07).

[25]  Leon Danon,et al.  Comparing community structure identification , 2005, cond-mat/0505245.

[26]  Marcos K. Aguilera,et al.  Matching events in a content-based subscription system , 1999, PODC '99.

[27]  D. Watts,et al.  Small Worlds: The Dynamics of Networks between Order and Randomness , 2001 .

[28]  M. Newman.  Power laws, Pareto distributions and Zipf's law , 2005 .

[29]  M. Karsten,et al.  An axiomatic basis for communication , 2007, SIGCOMM '07.

[30]  Matthias Grossglauser,et al.  Age matters: efficient route discovery in mobile ad hoc networks using encounter ages , 2003, MobiHoc '03.

[31]  Walter Willinger,et al.  An empirical approach to modeling inter-AS traffic matrices , 2005, IMC '05.

[32]  Mads Haahr,et al.  Social network analysis for routing in disconnected delay-tolerant MANETs , 2007, MobiHoc '07.

[33]  Pan Hui,et al.  How Small Labels Create Big Improvements , 2007, PerCom Workshops.

[34]  Pan Hui,et al.  Pocket switched networks and human mobility in conference environments , 2005, WDTN '05.

[35]  Anders Lindgren,et al.  Opportunistic content distribution in an urban setting , 2006, CHANTS '06.

[36]  Pan Hui,et al.  Distributed community detection in delay tolerant networks , 2007, MobiArch '07.

[37]  Martin Rosvall,et al.  An information-theoretic framework for resolving community structure in complex networks , 2007, Proceedings of the National Academy of Sciences.

[38]  Béla Bollobás,et al.  Random Graphs , 1985 .

[39]  Amin Vahdat,et al.  Epidemic Routing for Partially-Connected Ad Hoc Networks , 2009 .

[40]  David D. Clark,et al.  The design philosophy of the DARPA internet protocols , 1988, SIGCOMM '88.

[41]  Martin Mauve,et al.  A survey on position-based routing in mobile ad hoc networks , 2001, IEEE Netw..

[42]  Pan Hui,et al.  Impact of Human Mobility on the Design of Opportunistic Forwarding Algorithms , 2006, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[43]  Anders Lindgren,et al.  Probabilistic routing in intermittently connected networks , 2003, MOCO.

[44]  Ness B. Shroff,et al.  Delay and Capacity Trade-Offs in Mobile Ad Hoc Networks: A Global Perspective , 2006, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[45]  Mark Newman,et al.  Detecting community structure in networks , 2004 .

[46]  S. Okasha.  Altruism, Group Selection and Correlated Interaction , 2005, The British Journal for the Philosophy of Science.

[47]  Tristan Henderson,et al.  The changing usage of a mature campus-wide wireless network , 2004, MobiCom '04.

[48]  Albert-László Barabási,et al.  Statistical mechanics of complex networks , 2001, ArXiv.

[49]  Timur Friedman,et al.  Evaluating Mobility Pattern Space Routing for DTNs , 2005, Proceedings IEEE INFOCOM 2006. 25TH IEEE International Conference on Computer Communications.

[50]  J. Reichardt,et al.  Statistical mechanics of community detection. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[51]  Pan Hui,et al.  Pocket Switched Networking: Challenges, Feasibility and Implementation Issues , 2005, WAC.

[52]  Amit Kumar,et al.  Connectivity and inference problems for temporal networks , 2000, STOC '00.

[53]  Gaetano Borriello,et al.  Exploiting Mobility for Energy Efficient Data Collection in Wireless Sensor Networks , 2006, Mob. Networks Appl..

[54]  Eyal de Lara,et al.  User mobility for opportunistic ad-hoc networking , 2004, Sixth IEEE Workshop on Mobile Computing Systems and Applications.

[55]  Geoffrey M. Voelker,et al.  Access and mobility of wireless PDA users , 2003, MOCO.

[56]  Eric Paulos,et al.  The familiar stranger: anxiety, comfort, and play in public places , 2004, CHI.

[57]  Lada A. Adamic,et al.  Search in Power-Law Networks , 2001, Physical review. E, Statistical, nonlinear, and soft matter physics.

[58]  M. Newman,et al.  Identifying the role that individual animals play in their social network , 2004, q-bio/0403029.

[59]  Krishna P. Gummadi,et al.  Measurement and analysis of online social networks , 2007, IMC '07.

[60]  Xiangchuan Chen,et al.  Enabling Disconnected Transitive Communication in Mobile Ad Hoc Networks , 2001 .

[61]  M E J Newman,et al.  Finding and evaluating community structure in networks. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[62]  M E J Newman,et al.  Modularity and community structure in networks. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[63]  J. Hopfield,et al.  From molecular to modular cell biology , 1999, Nature.

[64]  Chen-Nee Chuah,et al.  Knowledge-based opportunistic forwarding in vehicular wireless ad hoc networks , 2005, 2005 IEEE 61st Vehicular Technology Conference.

[65]  Jie Wu,et al.  Small Worlds: The Dynamics of Networks between Order and Randomness , 2003 .

[66]  David Tse,et al.  Mobility increases the capacity of ad hoc wireless networks , 2002, TNET.

[67]  L. Tong,et al.  Energy Efficient Data Collection in Sensor Networks , 2022 .

[68]  Scott Shenker,et al.  Internet indirection infrastructure , 2002, SIGCOMM 2002.

[69]  Gary William Flake,et al.  Self-organization of the web and identification of communities , 2002 .

[70]  A. Clauset.  Finding local community structure in networks. , 2005, Physical review. E, Statistical, nonlinear, and soft matter physics.

[71]  Cecilia Mascolo,et al.  Adaptive routing for intermittently connected mobile ad hoc networks , 2005, Sixth IEEE International Symposium on a World of Wireless Mobile and Multimedia Networks.

[72]  Ellen W. Zegura,et al.  A message ferrying approach for data delivery in sparse mobile ad hoc networks , 2004, MobiHoc '04.

[73]  A. Barabasi,et al.  Hierarchical Organization of Modularity in Metabolic Networks , 2002, Science.

[74]  John Odentrantz,et al.  Markov Chains: Gibbs Fields, Monte Carlo Simulation, and Queues , 2000, Technometrics.

[75]  Susan T. Dumais,et al.  Searching to eliminate personal information management , 2006, CACM.

[76]  T. Vicsek,et al.  Uncovering the overlapping community structure of complex networks in nature and society , 2005, Nature.

[77]  Cauligi S. Raghavendra,et al.  Spray and wait: an efficient routing scheme for intermittently connected mobile networks , 2005, WDTN '05.

[78]  M. Newman,et al.  Finding community structure in very large networks. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[79]  Pan Hui,et al.  A socio-aware overlay for publish/subscribe communication in delay tolerant networks , 2007, MSWiM '07.

[80]  Sergei Maslov,et al.  Hierarchy measures in complex networks. , 2003, Physical review letters.

[81]  ChaintreauAugustin,et al.  Impact of Human Mobility on Opportunistic Forwarding Algorithms , 2007 .

[82]  Hari Balakrishnan,et al.  The design and implementation of an intentional naming system , 1999, SOSP.