60 likes | 254 Views
Bubble Rap: Social-based Forwarding in DTNs. Pan Hui, Jon Crowcroft, Eiko Yoneki University of Cambridge, Computer Laboratory Slides by Alex Papadimitriou. Bubble Rap: Social-based Forwarding in DTNs. Pocket Switched Networks (PSNs) Human mobility in terms of social structures
E N D
Bubble Rap: Social-based Forwarding in DTNs • Pan Hui, Jon Crowcroft, Eiko Yoneki • University of Cambridge, Computer Laboratory Slides by Alex Papadimitriou
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.
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.
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.
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).