Bubble Rap: Social-based Forwarding in DTNs

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Bubble Rap Social-based Forwarding in DTNs

• Pan Hui, Jon Crowcroft, Eiko Yoneki
• University of Cambridge, Computer Laboratory
• Slides by
• Alex Papadimitriou

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Bubble Rap Social-based Forwarding in DTNs

• Pocket Switched Networks (PSNs)
• Human mobility in terms of social structures
• Multitude of devices carried by people are
  dynamically networked.
• A PSN uses contact opportunities to allow humans
  to communicate without network infrastructure.
• Within a community some people are more popular
  and interact with more people than others (have
  high centrality), we call them hubs.
• Betweenness Centrality measures the number of
  times a node falls on the shortest path between
  two other nodes.
• Represents the importance of a node as a
  potential traffic relay for other nodes in the
  system.

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Bubble Rap Social-based Forwarding in DTNs

• Experimental Datasets
• Infocom05, Hong Kong, Cambridge, infocom06,
  reality.
• Two intuitions
• People have varying roles and popularities in
  society. The first part of the forwarding
  strategy is to forward messages to nodes which
  are more popular than the current node.
• People form communities in their social lives.
  The second part of the strategy is to identify
  the members of destination communities and to use
  them as relays.
• Assumptions
• Each node belongs to at least one community.
• Each node has a global ranking across the system
  and a local ranking for its local community. It
  may belong to multiple communities and have
  multiple local rankings.

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Bubble Rap Social-based Forwarding in DTNs

• Algorithm
• The sender node first bubbles the message up the
  ranking tree using the global ranking, until it
  reaches a node which is in the same community as
  the destination node.
• Then the local ranking is used. The message
  bubbles up the through the local ranking until
  the destination is reached or the message
  expires.
• The node needs to be able to compare rankings
  with nodes encountered and to push the message
  using a greedy approach.
• Whenever a message is delivered to the community,
  the original carrier can delete this message from
  the buffer.

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Bubble Rap Social-based Forwarding in DTNs

• Real Life
• First you try to forward the message via
  surrounding people more popular than you
  (politician), and then you bubble it up to
  well-known popular people in the wider-community
  (postman).

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Bubble Rap Social-based Forwarding in DTNs