ppt on

1. Presented by
Ramya R.

2. CONTENTS
 INTRODUCTION
 RELATED WORK
 THE PROPOSED ALGORITHM
 EVALUATION
 CONCLUSION
 REFERENCES

3. INTRODUCTION
 Delay tolerant network
 Real life examples
-MSNs
 Opportunistic routing of messages
 Enable nodes to make right forwarding decisions while routing
messages

4. Cont’d….
 The relationship defining the frequency and duration of
the connectivity between nodes has to be analyzed to route
messages efficiently
Ex: high school network
 A new metric that detects the quality of friendship
between the nodes either
Directly
Indirectly

5. RELATED WORK
General DTN Routing Algorithms
 Multicopy based
 Single-copy based
 Erasure-coding based

6. Multicopy based
 Exchange of messages
 The drawback is:
Excessive usage of bandwidth
Buffer space
Energy due to spreading of copies

7. Single copy based
 Based on movement of the nodes.
 In Max-Prop prioritization of the schedule of packets
that will be transmitted to other nodes or that will be
dropped from the buffer

8. Erasure-coding based
 The message is divided into large set of blocks
 Advantage
Robustness to failures
Increase the delivery rate

9. Contd…..
Social-Based Routing for MSNs
 Daly and Haahr use both social similarity and egocentric
betweenness metric to increase routing performance.
 Each node is assumed to have two rankings:
 global
 local.

10. Analysis of Node Relation

11. Friendship Community Formation
 Used in forwarding of messages.
 Three behavioral features of close friendships:
high frequency
 longevity
regularity
 A new metric, social pressures metric (SPM) to accurately
detect the quality of friendship.
 The link quality wi,j between each pair of nodes(i, j), is
defined as wi,j = 1/SPMi,j

12. ‘what would be the average delivery delay of node i’s continuously
generated messages if they followed the path <i,j,k>’?

13. Handling periodic variation in node Relation

14. EVALUATION
 Three metrics:
Message delivery ratio
Average cost
Routing efficiency

16. CONCLUSION
 New metric to detect friendship-based node relations
accurately.
 Presented a new routing algorithm in which a node forwards
its messages to those nodes that contain the destination node in
their friendship communities.
 Evaluated the proposed algorithm through simulations.
 Algorithm performs better than three benchmark algorithms
proposed previously.

17. REFERENCES
 J. Ott and D. Kutscher, “A Disconnection-Tolerant Transport for Drive-Thru
Internet Environments,” Proc. IEEE INFOCOM, 2005.
 Y. Wang, S. Jain, M. Martonosi, and K. Fall, “Erasure-Coding Based Routing
for Opportunistic Networks,” Proc. ACM SIGCOMM Workshop Delay-Tolerant
Networking, 2005.
 E. Daly and M. Haahr, “Social Network Analysis for Routing in
Disconnected Delay-Tolerant Manets,” Proc. ACM MobiHoc, 2007.
 E. Bulut, Z. Wang, and B.K. Szymanski, “Impact of Social Networks in
Delay Tolerant Routing,” Proc. IEEE GLOBECOM, 2009.
 Q. Li, S. Zhu, and G. Cao, “Routing in Selfish Delay Tolerant Networks,”
Proc. IEEE INFOCOM, 2010.