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Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks

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Waldir Moreira

The document discusses opportunistic networking, which involves highly dynamic networks utilizing mobile and static nodes for information exchange during intermittent connectivity situations. It outlines applications of delay/disruption tolerant networks (DTNs) in various environments such as disaster recovery, urban settings, and deep space communications, while presenting an overview of routing strategies and future directions. Additionally, it emphasizes the role of user willingness and device capabilities in shaping these networks.

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Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks Waldir Moreira and Paulo Mendes waldir.junior@ulusofona.pt Oct 26th, 2011 IEEE Latincom 2011, Belém-PA/Brasil
Agenda • Introduction • The case of Delay/Disruption Tolerant Networks • Use cases • Routing over Opportunistic Networks • Future Directions 2
Introduction 3
Picture today • Users are eager for retrieving/providing information • Popularization of portable devices 4
Opportunistic Networking User Willingness Powerful Devices 5
Opportunistic Networking Opportunistic Networking 6
Straightforward Definition OppNets are highly dynamic, composed of mobile and static nodes (i.e., devices) and take advantages of opportunistic time- varying contacts among users carrying them to exchange information 7
OppNet Elements • Nodes - PDAs, cell phones, anything with networking capabilities • Contacts - Scheduled (i.e., mules, buses, LEO satellites) - Opportunistic (i.e., random contact with a strange) • Information - Anything that can deal with the high queueing delays 8
General OppNets Characteristics • Occasional contacts • Intermittent connectivity • Highly mobile and fixed nodes • Power-constrained devices • Possible nonexistence of e2e paths 9
Application Scenarios • Disaster and Emergency Networks • Animal-Tracking Networks • Sensor Networks • Inter-Planetary Networks • Delay/Disruption Tolerant Networks 10
The case of Delay/ Disruption Tolerant Networks 11
Interplanetary Internet "to permit interoperation of the Internet resident on Earth with other remotely located internets resident on other planets or spacecraft in transit." [9] Interplanetary Internet Home 12
Interplanetary Internet [13] A. McMahon, S. Farrell. Delay- and Disruption-Tolerant Networking, IEEE Internet Computing, 2009 13
IPN Characteristics • Significant propagation delays - 4 minutes one-way light-trip time between Earth and Mars • Intermittent connectivity - Planetary movement • Low and highly asymmetric bandwidth • Relatively high bit-error rate 14
History • Interplanetary Internet envisioned by Vint Cerf (1997) • Collaboration between Cerf and NASA’s Jet Propulsion Laboratory (1998) • Interplanetary Internet Research Group (IPNRG) • Interplanetary Internet (IPN): Architectural Definition (2001) • Delay-Tolerant Network Architecture: The Evolving Interplanetary Internet (2002) • IPNRG -> DTNRG • Delay-Tolerant Networking Architecture (2007) 15
Simple DTN Definition Occasionally-connected networks where partitions are rather frequent 16
Regular Assumptions • New networks do not have what it takes: - Continuous, bidirectional e2e paths - Short round-trips - Symmetric data rates - Low error rates 17
Why the need for DTN? • DTNs can cope: - Intermitent connectivity - Long/Variable delay - Asymmetric data rates - High error rates 18
DTN Architecture • Bundle layer - e2e message-oriented overlay based on hop-by-hop transfer with persistent storage to overcome network interruption - Focus on reliable transport structure than in routing itself 19
Store-Carry-and-Forward Paradigm [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 20
Use Cases 21
Different Environments • Disruptive environments: - Sparse scenarios where communication is established through sporadic contacts • Urban environments -Dense scenarios with communication suffering different interference levels 22
Disruptive Environments Deep Space Communications • Purpose: provide communication means for manned/robotic exploration • Main challenges: very long delays, sparseness, shadow areas and spacecraft lifetime • Function: Information and commands are exchanged between landers/rovers and earth station through orbiters 23
Disruptive Environments Deep Space Communications [19] News on Deep Space Networking [12] Mars Reconnaissance Orbiter 24
Disruptive Environments Noise Monitoring • Purpose: keep track of noise to ensure acceptable levels • Main challenges: high cost of equipments and communication medium • Function: buses (i.e., data mules) collect data from monitoring stations 25
Disruptive Environments Networks for Developing World • Purpose: provide asynchronous Internet access despite the scarce/expensive infrastructure • Main challenges: long delays and scarce/expensive infrastructure • Function: data is sent/retrieved either through USB stick carried by a motorbiker or via dial-up connection 26
Disruptive Environments Networks for Developing World [10] S. Jain, K. Fall, R. Patra, Routing in a delay tolerant network, 2004 [20] News on Pigeon Carrier 27
Disruptive Environments Earthquake Monitoring • Purpose: keep track of seismic activity • Main challenges: very long delays • Function: activity is relayed through nodes until reaches the sink 28
Disruptive Environments Earthquake Monitoring [14] Middle America Subduction Experiment (MASE) 29
Disruptive Environments Undersea Acoustic Networking • Purpose: provide connectivity to autonomous underwater vehicles • Main challenges: delay, and challenging medium • Function: information exchanged between AUV/subs and command center through repeaters, buoys, and sattelite links 30
Disruptive Environments Undersea Acoustic Networking [21] Seaweb Network 31
Disruptive Environments Zebranet • Purpose: Study zebra movements through collars carried by them • Main challenges: energy constraints • Function: collars opportunistically exchange GPS location later then obtained by scientists 32
Disruptive Environments Zebranet 33
Disruptive Environments Sámi Network Connectivity • Purpose: provide location information on reindeer herds • Main challenges: very little infrastructure and sparseness • Function: herds locations is carried on snowmobiles back to villages 34
Disruptive Environments Tactical Military Networks • Purpose: establish quick communication means among military soldiers, vehicles, and aircrafts • Main challenges: high disruption and partition • Function: information is relayed among military units 35
Disruptive Environments Tactical Military Networks [15] MITRE Corporation (C2 On-the-Move Network, Digital Over-the-Horizon Relay) 36
Urban Environments Opportunistic Sensing • Purpose: gather information from sensing systems • Main challenges: short contact times • Function: sensor present in different devices gather information which is then collected mobile devices (i.e., custodian) to be transfered to the sensing system central 37
Urban Environments Opportunistic Sensing [3] CamMobSens - Cambridge University Pollution Monitoring Initiative 38
Routing over Opportunistic Networks 39
What is it about? Considers any contact among nodes and forwarding decisions are made using locally collected knowledge about node behavior to predict which nodes are likely to deliver a content or bring it closer to the destination 40
2000-2010 Analysis [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 41
Existing Taxonomies [16] 42
Major Routing Families [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 43
Flooding-based Approaches • Function: replicate messages at every encounter • Advantages: optimal delivery probability • Disadvantages: elevated resource consumption 44
Flooding-based Approaches • Epidemic [24] A. Vahdat, D. Becker, Epidemic routing for partially connected ad hoc networks, Tech. Rep. CS-200006, Duke University, 2000. 45
Forwarding-based Approaches • Function: only one copy of the message traverses the network • Advantages: spare resources • Disadvantages: low delivery rate and high delay 46
Forwarding-based Approaches • Direct transmission - Forwarding only to the destination • Utility-based routing with 1-hop diffusion - Function based on encounter timers [23] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Efficient routing in intermittently connected mobile networks: the single-copy case, 2008 47
Replication-based Approaches • Function: spread enough copies to quickly reach destination • Advantages: increase delivery probability while sparing resources • Disadvantages: metadata overhead 48
Replication-based Approaches • Encounter-based • Resource Usage • Social Similarity 49
Replication-based Approaches Encounter-based • Frequency Encounter: history of encounters with a specific destination - Encounter-Based Routing (EBR) * Counts the number of contacts (Current Window Counter) * Determines node’s past rate of encounters (Encounter Value) [18] S. Nelson, M. Bakht, R. Kravets, Encounter-based routing in DTNs, 2009 50
Replication-based Approaches Encounter-based • Aging Encounter: time elapsed since last encounter with destination - FResher Encounter SearcH (FRESH) * Time elapsed since last encounter [7] H. Dubois-Ferriere, M. Grossglauser, M. Vetterli, Age matters: efficient route discovery in mobile ad hoc networks using encounter ages, 2003 51
Replication-based Approaches Resource Usage • Aging Message: avoid messages to be kept being forwarded - Spray and Wait * Spread L number of copies * Direct transmission [22] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Spray and wait: an efficient routing scheme for intermittently connected mobile networks, 2005 52
Replication-based Approaches Resource Usage • Resource Allocation: forwarding decisions that wisely use available resources - RAPID * Replication occurs based on the effect that it may have on a predefined performance metric [2] A. Balasubramanian, B. Levine, A. Venkataramani, Dtn routing as a resource allocation problem, 2007 53
Social Aspects: The New Trend • Since 2007 • Have shown great potential • Use social relationship • Much wiser decisions 54
Replication-based Approaches Social Similarity • Community Detection: creation of communities considering people social relationships - Bubble Rap * Forwarding based on community and local/ global centrality [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, 2011 55
Replication-based Approaches Social Similarity • Shared Interests: nodes with the same interest as destination are good forwarders - SocialCast * predicted node’s co-location (probability of nodes being co-located with others) * change in degree of connectivity (mobility and changes in neighbor sets) [5] P. Costa, C. Mascolo, M. Musolesi, G. P. Picco, Socially-aware routing for publish-subscribe in delay-tolerant mobile ad hoc networks, 2008 56
Replication-based Approaches Social Similarity • Node Popularity: use of social information to generate ranks to nodes based on their position on a social graph - PeopleRank * Forwarding based on social ranking of nodes [17] A. Mtibaa, M. May, M. Ammar, C. Diot, Peoplerank: Combining social and contact information for opportunistic forwarding, 2010 57
Drawbacks with Detection of Social Structures • Community detection, shared interests, node popularity • Communities are statically defined • Do not consider the age of contacts when computing the centrality • Strong assumptions • Full knowledge on social information is not enough • Some social metrics (e.g., betweenness centrality) can lead to node homogeneity [8] T. Hossmann, T. Spyropoulos, F. Legendre, Know thy neighbor: Towards optimal mapping of contacts to social graphs for dtn routing, 2010 58
Future Directions 59
Recap • Lots of users • Different new types of networking • Many options to perform forwarding 60
Community-based Forwarding • Based on destination's community - e.g., Kclique [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, 2011 61
Interest-based Forwarding • Data travels based on interest • Publish-Subscribe paradigm • Next-hop node is chosen based on its interest in the message's content 62
Information-Centric Forwarding • Focus on the content and its interested parties • Data is labeled (which is used to retrieve it) • Users seamlessly exchange data among themselves [1] The FP7 4WARD Project 63
Acknowledgements To FCT for financial support via PhD grant (SFRH/BD/62761/2009) 64
Your view What do you envision ?? 65
References [1] 4WARD Project, The FP7 - http://www.4ward-project.eu/index.php?id=29 [2] A. Balasubramanian, B. Levine, A. Venkataramani, Dtn routing as a resource allocation problem, in: Proceedings of ACM SIGCOMM, Kyoto, Japan, August, 2007. [3] CamMobSens - Cambridge University Pollution Monitoring Initiative - http://www.escience.cam.ac.uk/mobiledata/ [4] V. Cerf, S. Burleigh, A. Hooke, L. Torgerson, R. Durst, K. Scott, K. Fall, H. Weiss, Delay tolerant network architecture, IETF Network Working Group. RFC 4838, 2007. [5] P. Costa, C. Mascolo, M. Musolesi, G. P. Picco, Socially-aware routing for publish-subscribe in delay-tolerant mobile ad hoc networks, Selected Areas in Communications, IEEE Journal on 26 (5) (2008) 748–760. [6] Delay-Tolerant Networks Home - http://www.dtnrg.org/ [7] H. Dubois-Ferriere, M. Grossglauser, M. Vetterli, Age matters: efficient route discovery in mobile ad hoc networks using encounter ages, in: Proceedings of ACM MobiHoc, Annapolis, USA, June, 2003. [8] T. Hossmann, T. Spyropoulos, F. Legendre, Know thy neighbor: Towards optimal mapping of contacts to social graphs for dtn routing, in: Proceedings of IEEE INFOCOM, San Diego, USA, March, 2010. [9] Interplanetary Internet Home - http://www.ipnsig.org/ [10] S. Jain, K. Fall, R. Patra, Routing in a delay tolerant network, in: Proceedings of the ACM SIGCOMM, Portland, USA, August,2004. [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, To appear in: Mobile Computing, IEEE Transactions on, 2011. [12] Mars Reconnaissance Orbiter - http://www.nasa.gov/mission_pages/MRO/news/mro-20060912.html [13] A. McMahon, S. Farrell. Delay- and Disruption-Tolerant Networking. IEEE Internet Computing, 2009. 66
References [14] Middle America Subduction Experiment (MASE) - http://www.gps.caltech.edu/~clay/MASEdir/MASEprogress_report.html#Figure1 [15] MITRE Corporation (US Marine Corps) (Presentation on C2 On-the-Move Network, Digital Over-the-Horizon Relay) - http://www.ietf.org/proceedings/65/slides/DTNRG-2.pdf [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” Tech. Rep. SITI-TR-11-02, Research Unit in Informatics Systems and Technologies (SITI), University Lusofona, February, 2011. [17] A. Mtibaa, M. May, M. Ammar, C. Diot, Peoplerank: Combining social and contact information for opportunistic forwarding, in: Proceedings of INFOCOM, San Diego, USA, March, 2010. [18] S. Nelson, M. Bakht, R. Kravets, Encounter-based routing in DTNs, in: Proceedings of INFOCOM, Rio de Janeiro, Brazil, April, 2009. [19] News on Deep Space Networking - http://www.engadget.com/2008/11/19/nasas-interplanetary-internet-tests-a- success-vint-cerf-triump/ [20] News on Pigeon Carrier - http://www.dailymail.co.uk/news/article-1212333/Pigeon-post-faster-South-Africas- Telkom.html [21] Seaweb Network (Presentation)- http://www.ietf.org/proceedings/65/slides/DTNRG-14.pdf [22] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Spray and wait: an efficient routing scheme for intermittently connected mobile networks, in: Proceedings of ACM SIGCOMM WDTN, Philadelphia, USA, August, 2005. [23] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Efficient routing in intermittently connected mobile networks: the single-copy case, IEEE/ACM Trans. Netw. 16 (1) (2008) 63–76. [24] A. Vahdat, D. Becker, Epidemic routing for partially connected ad hoc networks, Tech. Rep. CS-200006, Duke University, 2000. [25] F. Warthman, Delay-tolerant networks (dtns): A tutorial, Warthman Associates. Version 1.1, May, 2003. 67
Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks Waldir Moreira and Paulo Mendes waldir.junior@ulusofona.pt Oct 26th, 2011 IEEE Latincom 2011, Belém-PA/Brasil

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Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks

  • 1. Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks Waldir Moreira and Paulo Mendes [email protected] Oct 26th, 2011 IEEE Latincom 2011, Belém-PA/Brasil
  • 2. Agenda • Introduction • The case of Delay/Disruption Tolerant Networks • Use cases • Routing over Opportunistic Networks • Future Directions 2
  • 4. Picture today • Users are eager for retrieving/providing information • Popularization of portable devices 4
  • 5. Opportunistic Networking User Willingness Powerful Devices 5
  • 6. Opportunistic Networking Opportunistic Networking 6
  • 7. Straightforward Definition OppNets are highly dynamic, composed of mobile and static nodes (i.e., devices) and take advantages of opportunistic time- varying contacts among users carrying them to exchange information 7
  • 8. OppNet Elements • Nodes - PDAs, cell phones, anything with networking capabilities • Contacts - Scheduled (i.e., mules, buses, LEO satellites) - Opportunistic (i.e., random contact with a strange) • Information - Anything that can deal with the high queueing delays 8
  • 9. General OppNets Characteristics • Occasional contacts • Intermittent connectivity • Highly mobile and fixed nodes • Power-constrained devices • Possible nonexistence of e2e paths 9
  • 10. Application Scenarios • Disaster and Emergency Networks • Animal-Tracking Networks • Sensor Networks • Inter-Planetary Networks • Delay/Disruption Tolerant Networks 10
  • 11. The case of Delay/ Disruption Tolerant Networks 11
  • 12. Interplanetary Internet "to permit interoperation of the Internet resident on Earth with other remotely located internets resident on other planets or spacecraft in transit." [9] Interplanetary Internet Home 12
  • 13. Interplanetary Internet [13] A. McMahon, S. Farrell. Delay- and Disruption-Tolerant Networking, IEEE Internet Computing, 2009 13
  • 14. IPN Characteristics • Significant propagation delays - 4 minutes one-way light-trip time between Earth and Mars • Intermittent connectivity - Planetary movement • Low and highly asymmetric bandwidth • Relatively high bit-error rate 14
  • 15. History • Interplanetary Internet envisioned by Vint Cerf (1997) • Collaboration between Cerf and NASA’s Jet Propulsion Laboratory (1998) • Interplanetary Internet Research Group (IPNRG) • Interplanetary Internet (IPN): Architectural Definition (2001) • Delay-Tolerant Network Architecture: The Evolving Interplanetary Internet (2002) • IPNRG -> DTNRG • Delay-Tolerant Networking Architecture (2007) 15
  • 16. Simple DTN Definition Occasionally-connected networks where partitions are rather frequent 16
  • 17. Regular Assumptions • New networks do not have what it takes: - Continuous, bidirectional e2e paths - Short round-trips - Symmetric data rates - Low error rates 17
  • 18. Why the need for DTN? • DTNs can cope: - Intermitent connectivity - Long/Variable delay - Asymmetric data rates - High error rates 18
  • 19. DTN Architecture • Bundle layer - e2e message-oriented overlay based on hop-by-hop transfer with persistent storage to overcome network interruption - Focus on reliable transport structure than in routing itself 19
  • 20. Store-Carry-and-Forward Paradigm [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 20
  • 21. Use Cases 21
  • 22. Different Environments • Disruptive environments: - Sparse scenarios where communication is established through sporadic contacts • Urban environments -Dense scenarios with communication suffering different interference levels 22
  • 23. Disruptive Environments Deep Space Communications • Purpose: provide communication means for manned/robotic exploration • Main challenges: very long delays, sparseness, shadow areas and spacecraft lifetime • Function: Information and commands are exchanged between landers/rovers and earth station through orbiters 23
  • 24. Disruptive Environments Deep Space Communications [19] News on Deep Space Networking [12] Mars Reconnaissance Orbiter 24
  • 25. Disruptive Environments Noise Monitoring • Purpose: keep track of noise to ensure acceptable levels • Main challenges: high cost of equipments and communication medium • Function: buses (i.e., data mules) collect data from monitoring stations 25
  • 26. Disruptive Environments Networks for Developing World • Purpose: provide asynchronous Internet access despite the scarce/expensive infrastructure • Main challenges: long delays and scarce/expensive infrastructure • Function: data is sent/retrieved either through USB stick carried by a motorbiker or via dial-up connection 26
  • 27. Disruptive Environments Networks for Developing World [10] S. Jain, K. Fall, R. Patra, Routing in a delay tolerant network, 2004 [20] News on Pigeon Carrier 27
  • 28. Disruptive Environments Earthquake Monitoring • Purpose: keep track of seismic activity • Main challenges: very long delays • Function: activity is relayed through nodes until reaches the sink 28
  • 29. Disruptive Environments Earthquake Monitoring [14] Middle America Subduction Experiment (MASE) 29
  • 30. Disruptive Environments Undersea Acoustic Networking • Purpose: provide connectivity to autonomous underwater vehicles • Main challenges: delay, and challenging medium • Function: information exchanged between AUV/subs and command center through repeaters, buoys, and sattelite links 30
  • 31. Disruptive Environments Undersea Acoustic Networking [21] Seaweb Network 31
  • 32. Disruptive Environments Zebranet • Purpose: Study zebra movements through collars carried by them • Main challenges: energy constraints • Function: collars opportunistically exchange GPS location later then obtained by scientists 32
  • 34. Disruptive Environments Sámi Network Connectivity • Purpose: provide location information on reindeer herds • Main challenges: very little infrastructure and sparseness • Function: herds locations is carried on snowmobiles back to villages 34
  • 35. Disruptive Environments Tactical Military Networks • Purpose: establish quick communication means among military soldiers, vehicles, and aircrafts • Main challenges: high disruption and partition • Function: information is relayed among military units 35
  • 36. Disruptive Environments Tactical Military Networks [15] MITRE Corporation (C2 On-the-Move Network, Digital Over-the-Horizon Relay) 36
  • 37. Urban Environments Opportunistic Sensing • Purpose: gather information from sensing systems • Main challenges: short contact times • Function: sensor present in different devices gather information which is then collected mobile devices (i.e., custodian) to be transfered to the sensing system central 37
  • 38. Urban Environments Opportunistic Sensing [3] CamMobSens - Cambridge University Pollution Monitoring Initiative 38
  • 40. What is it about? Considers any contact among nodes and forwarding decisions are made using locally collected knowledge about node behavior to predict which nodes are likely to deliver a content or bring it closer to the destination 40
  • 41. 2000-2010 Analysis [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 41
  • 43. Major Routing Families [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” SITI, University Lusofona, February, 2011 43
  • 44. Flooding-based Approaches • Function: replicate messages at every encounter • Advantages: optimal delivery probability • Disadvantages: elevated resource consumption 44
  • 45. Flooding-based Approaches • Epidemic [24] A. Vahdat, D. Becker, Epidemic routing for partially connected ad hoc networks, Tech. Rep. CS-200006, Duke University, 2000. 45
  • 46. Forwarding-based Approaches • Function: only one copy of the message traverses the network • Advantages: spare resources • Disadvantages: low delivery rate and high delay 46
  • 47. Forwarding-based Approaches • Direct transmission - Forwarding only to the destination • Utility-based routing with 1-hop diffusion - Function based on encounter timers [23] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Efficient routing in intermittently connected mobile networks: the single-copy case, 2008 47
  • 48. Replication-based Approaches • Function: spread enough copies to quickly reach destination • Advantages: increase delivery probability while sparing resources • Disadvantages: metadata overhead 48
  • 50. Replication-based Approaches Encounter-based • Frequency Encounter: history of encounters with a specific destination - Encounter-Based Routing (EBR) * Counts the number of contacts (Current Window Counter) * Determines node’s past rate of encounters (Encounter Value) [18] S. Nelson, M. Bakht, R. Kravets, Encounter-based routing in DTNs, 2009 50
  • 51. Replication-based Approaches Encounter-based • Aging Encounter: time elapsed since last encounter with destination - FResher Encounter SearcH (FRESH) * Time elapsed since last encounter [7] H. Dubois-Ferriere, M. Grossglauser, M. Vetterli, Age matters: efficient route discovery in mobile ad hoc networks using encounter ages, 2003 51
  • 52. Replication-based Approaches Resource Usage • Aging Message: avoid messages to be kept being forwarded - Spray and Wait * Spread L number of copies * Direct transmission [22] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Spray and wait: an efficient routing scheme for intermittently connected mobile networks, 2005 52
  • 53. Replication-based Approaches Resource Usage • Resource Allocation: forwarding decisions that wisely use available resources - RAPID * Replication occurs based on the effect that it may have on a predefined performance metric [2] A. Balasubramanian, B. Levine, A. Venkataramani, Dtn routing as a resource allocation problem, 2007 53
  • 54. Social Aspects: The New Trend • Since 2007 • Have shown great potential • Use social relationship • Much wiser decisions 54
  • 55. Replication-based Approaches Social Similarity • Community Detection: creation of communities considering people social relationships - Bubble Rap * Forwarding based on community and local/ global centrality [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, 2011 55
  • 56. Replication-based Approaches Social Similarity • Shared Interests: nodes with the same interest as destination are good forwarders - SocialCast * predicted node’s co-location (probability of nodes being co-located with others) * change in degree of connectivity (mobility and changes in neighbor sets) [5] P. Costa, C. Mascolo, M. Musolesi, G. P. Picco, Socially-aware routing for publish-subscribe in delay-tolerant mobile ad hoc networks, 2008 56
  • 57. Replication-based Approaches Social Similarity • Node Popularity: use of social information to generate ranks to nodes based on their position on a social graph - PeopleRank * Forwarding based on social ranking of nodes [17] A. Mtibaa, M. May, M. Ammar, C. Diot, Peoplerank: Combining social and contact information for opportunistic forwarding, 2010 57
  • 58. Drawbacks with Detection of Social Structures • Community detection, shared interests, node popularity • Communities are statically defined • Do not consider the age of contacts when computing the centrality • Strong assumptions • Full knowledge on social information is not enough • Some social metrics (e.g., betweenness centrality) can lead to node homogeneity [8] T. Hossmann, T. Spyropoulos, F. Legendre, Know thy neighbor: Towards optimal mapping of contacts to social graphs for dtn routing, 2010 58
  • 60. Recap • Lots of users • Different new types of networking • Many options to perform forwarding 60
  • 61. Community-based Forwarding • Based on destination's community - e.g., Kclique [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, 2011 61
  • 62. Interest-based Forwarding • Data travels based on interest • Publish-Subscribe paradigm • Next-hop node is chosen based on its interest in the message's content 62
  • 63. Information-Centric Forwarding • Focus on the content and its interested parties • Data is labeled (which is used to retrieve it) • Users seamlessly exchange data among themselves [1] The FP7 4WARD Project 63
  • 64. Acknowledgements To FCT for financial support via PhD grant (SFRH/BD/62761/2009) 64
  • 65. Your view What do you envision ?? 65
  • 66. References [1] 4WARD Project, The FP7 - http://www.4ward-project.eu/index.php?id=29 [2] A. Balasubramanian, B. Levine, A. Venkataramani, Dtn routing as a resource allocation problem, in: Proceedings of ACM SIGCOMM, Kyoto, Japan, August, 2007. [3] CamMobSens - Cambridge University Pollution Monitoring Initiative - http://www.escience.cam.ac.uk/mobiledata/ [4] V. Cerf, S. Burleigh, A. Hooke, L. Torgerson, R. Durst, K. Scott, K. Fall, H. Weiss, Delay tolerant network architecture, IETF Network Working Group. RFC 4838, 2007. [5] P. Costa, C. Mascolo, M. Musolesi, G. P. Picco, Socially-aware routing for publish-subscribe in delay-tolerant mobile ad hoc networks, Selected Areas in Communications, IEEE Journal on 26 (5) (2008) 748–760. [6] Delay-Tolerant Networks Home - http://www.dtnrg.org/ [7] H. Dubois-Ferriere, M. Grossglauser, M. Vetterli, Age matters: efficient route discovery in mobile ad hoc networks using encounter ages, in: Proceedings of ACM MobiHoc, Annapolis, USA, June, 2003. [8] T. Hossmann, T. Spyropoulos, F. Legendre, Know thy neighbor: Towards optimal mapping of contacts to social graphs for dtn routing, in: Proceedings of IEEE INFOCOM, San Diego, USA, March, 2010. [9] Interplanetary Internet Home - http://www.ipnsig.org/ [10] S. Jain, K. Fall, R. Patra, Routing in a delay tolerant network, in: Proceedings of the ACM SIGCOMM, Portland, USA, August,2004. [11] P. Hui, J. Crowcroft, E. Yoneki, BUBBLE Rap: Social-based Forwarding in Delay Tolerant Networks, To appear in: Mobile Computing, IEEE Transactions on, 2011. [12] Mars Reconnaissance Orbiter - http://www.nasa.gov/mission_pages/MRO/news/mro-20060912.html [13] A. McMahon, S. Farrell. Delay- and Disruption-Tolerant Networking. IEEE Internet Computing, 2009. 66
  • 67. References [14] Middle America Subduction Experiment (MASE) - http://www.gps.caltech.edu/~clay/MASEdir/MASEprogress_report.html#Figure1 [15] MITRE Corporation (US Marine Corps) (Presentation on C2 On-the-Move Network, Digital Over-the-Horizon Relay) - http://www.ietf.org/proceedings/65/slides/DTNRG-2.pdf [16] W. Moreira and P. Mendes, “Survey on opportunistic routing for delay tolerant networks,” Tech. Rep. SITI-TR-11-02, Research Unit in Informatics Systems and Technologies (SITI), University Lusofona, February, 2011. [17] A. Mtibaa, M. May, M. Ammar, C. Diot, Peoplerank: Combining social and contact information for opportunistic forwarding, in: Proceedings of INFOCOM, San Diego, USA, March, 2010. [18] S. Nelson, M. Bakht, R. Kravets, Encounter-based routing in DTNs, in: Proceedings of INFOCOM, Rio de Janeiro, Brazil, April, 2009. [19] News on Deep Space Networking - http://www.engadget.com/2008/11/19/nasas-interplanetary-internet-tests-a- success-vint-cerf-triump/ [20] News on Pigeon Carrier - http://www.dailymail.co.uk/news/article-1212333/Pigeon-post-faster-South-Africas- Telkom.html [21] Seaweb Network (Presentation)- http://www.ietf.org/proceedings/65/slides/DTNRG-14.pdf [22] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Spray and wait: an efficient routing scheme for intermittently connected mobile networks, in: Proceedings of ACM SIGCOMM WDTN, Philadelphia, USA, August, 2005. [23] T. Spyropoulos, K. Psounis, C. S. Raghavendra, Efficient routing in intermittently connected mobile networks: the single-copy case, IEEE/ACM Trans. Netw. 16 (1) (2008) 63–76. [24] A. Vahdat, D. Becker, Epidemic routing for partially connected ad hoc networks, Tech. Rep. CS-200006, Duke University, 2000. [25] F. Warthman, Delay-tolerant networks (dtns): A tutorial, Warthman Associates. Version 1.1, May, 2003. 67
  • 68. Opportunistic Networking: Extending Internet Communications Through Spontaneous Networks Waldir Moreira and Paulo Mendes [email protected] Oct 26th, 2011 IEEE Latincom 2011, Belém-PA/Brasil