MULTICASTING IN DELAY TOLERANT NETWORK

Submitted BySHIVI SHUKLA

ABMTI13039

Under The Supervision of Dr Yatindra Nath Singh Professor, EE Dept

IIT, Kanpur

Department of Computer ScienceBanasthali University

ROUTING IN DELAY TOLERANT NETWORKS

Presented By-Shivi Shukla

TABLE OF CONTENT

Introduction to DTN Salient features Main Principle Protocol architecture Bundle Protocol Routing in DTN Classification of Routing Algorithms Performance Analysis Conclusion

INTRODUCTION TO DTN

Idea of DTN is taken from InterPlaNetary networks(IPN)

Wireless Ad-hoc network

Tolerates the intermittent connectivity ,longer delays

and prevent data loss

Tolerates High Latency Tolerates Asymmetric Data Rates Prevent Data Loss Tolerates Intermittent Connectivity Supports Heterogeneous Environment Tolerates Long Queuing Delays

SALIENT FEATURES OF DTN

Bundle-Protocol

Provided by

MAIN PRINCIPLE

PROTOCOL STACK

Enables Retransmission

Tolerates Intermittent connection

Supports any type of connectivity

• Scheduled, opportunistic, predicted

Supports late binding

• To support the heterogeneous environment

BUNDLE PROTOCOL

To choose the best path is not the case here.

End to end path can never be constructed.

Messages are forwarded when any contact is found.

ROUTING IN DTN

For Example

• Every DTN node belongs to some particular network (area).

• Where it meets some nodes so often and these nodes become friends of that node.

• A particular node can depend upon their friends to receive any message.

• When the network system has been established, every node will declare their friends according to the proximity.

M

C

G

J

L

E

I

H

F

DK

A

GRAPHICAL REPRESENTATION OF RELIABLE NODES

Nodes Friends A D,E,F,KB I,K,DC J,L,M,E,FD B,A,FE F,C,A,J,KF C,K,D,A,E,JG L,MH N,K,I,JI J,H,BJ H,F,E,C,IK A,E,B,F,HL C,GM C,GN H,D

Routing Protocols

Flooding BasedDire

ct Contact

Epidemic

Two-Hop

Tree Base

d

Spray

and Wait

Forwarding Based

NECTAR

Per-Hop

Per-Contact

Source

Routing

CRHC

Broadly classified into two categories: • Flooding Based• Forwarding Based

ROUTING ALGORITHMS CLASSIFICATION

Work even with no knowledge about the

network.

Any number of replicas can be flooded to the

network.

Number of replicas generated can be either :•Replication Based- number of replicas in the network can be n-1.•Quota Based – limited replicas present in the network.

FLOODING BASED APPROACH

•Source directly forwards the bundle to the destination.•Single message transmission.•Less resource consumption.•High delay in delivering the message.

A CB

A C

B

Message for C

×

At t=0 At t=1

DIRECT CONTACT

•Each node replicates the message to every other node after checking the summary vector.•The summary vector is maintained at each node that stores the information about all the messages.

A

C

B

D

E

F

Send to every node in contact

EPIDEMIC ROUTING

•Source node replicates the message to an adequate number of relay nodes.•Message will be delivered to the destination within two hops only.

A

C

B

D E

FG

H

Source

Destination× ×

At t=0

A

C

B

D E

FG

H

Source

Destination

D

At t=1

TWO-HOP ROUTING

•Each node can replicate to only two child nodes in binary tree approach.•Limiting the number of replicas can limit the breadth and depth of tree.

A

C

ED FB

G

Source

TREE BASED FLOODING

Consist of two phases: •Spray: source node replicates the message to the m nodes and these m nodes will further relay the message to m relay nodes.•Wait: If the destination is not found in spray phase then the relay nodes will store the message and performs direct transmission to the destination.

SPRAY AND WAIT

Work with some knowledge of the

network.

Messages are not replicated but

forwarded.

•Works efficiently with less number of nodes.

FORWARDING BASED

•Each node maintains neighborhood index.•Neighborhood index contains the value of meeting frequency of node with every other node.•The messages are forwarded to the nodes having higher value of neighborhood index.

AC

B

×

NI=1

NI=5

NECTAR

Consist of two phases:•Route discovery: route is discovered by sending control packets towards a destination node.•Route maintenance: if a link failure isdetected then a route error message is broadcasted by the source.

SOURCE ROUTING

•Each intermediate node will decide the next node to which the packet isto be forwarded.•More updated information is used.

A

CE

F

D

B

G

2

14 4

12

3Source

Destination

PER HOP ROUTING

•Most updated information is used.•When intermediate node receives any message for a particular destination then it checks the current Up contacts and select the appropriate node for relaying the message.

A

CE

F

D

B

G

2

14 4

12

3Source

DestinationA

CE

F

D

B

G

2

14 4

12

3Source

Destination

2

At t=0 At t=1

PER CONTACT ROUTING

•Introduces the concept of clustering (i.e. grouping) of nodes on the basis of link property and communication characteristics.•After formation of clusters, a cluster head is selected based on higher stability or the higher quality among all nodes and takes routing decisions.

HIERARCHICAL FORWARDING AND CLUSTER CONTROL ROUTING

Protocol Number of messages generated

Message delivery ratio

Average delay Resource consumption

Direct contact Single Low High Less

Epidemic N-1 High Low High

Two-hop K Medium Medium Less

Tree based 1+log(N/2) Medium High Medium

Spray and Wait

≥K Medium Medium Medium

Table1: Comparison of flooding based routing algorithms

N= Total number of nodes present in the networkK= Optimal number of nodes to assure the delivery

COMPARISON AMONG FLOODING BASED ROUTING ALGORITHMS

Protocol Information maintenance

Message delivery ratio

Average delay

Resource consumption

NECTAR Medium High Normal Medium

Per-hop Medium Medium Medium Low

Per-contact Medium High Low Medium

Source Normal Low High Low

CRHC High High Normal Medium

Table 2: Comparison of forwarding based routing algorithms

COMPARISON AMONG FORWARDING BASED ROUTING ALGORITHM

•Each algorithm has its own pros and cons, so selection of routing protocol depends on application environment.•Algorithms based on flooding approachhave a better delivery ratio but consume more resources in comparison to forwarding based algorithms.•Comparison of the different algorithms are shown in the tabular chart.

•Each algorithm has its own pros and cons, so selection of routing protocol depends on application environment.•Algorithms based on flooding approachhave a better delivery ratio but consume more resources in comparison to forwarding based algorithms.

CONCLUSION

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26(5), pp. 828-836.• 2. Sushant Jain,Kevin Fall,Rabin Patra (2004) 'Routing in a Delay Tolerant Network', ACM ,

(1581138628/ 04/0008), pp. 145-157.• 3.http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5684272&url=http%3A%2F

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• 6. D.Hua, X.Du, Y.Qian, S.Yan (2009) 'A DTN Routing Protocol Based on Hierarchy Forwarding and Cluster Control', IEEE, DO1 10.1109(CIS.2009.150), pp. 397-401.

• 7. Jie Wu and Yunsheng Wang (2012) 'Social Feature-based Multi-path Routing in Delay Tolerant Networks', IEEE INFOCOM, (978-1-4673-0775-8/12), pp. 1368-1376.

• 8. Maurice J. Khabbaz, Chadi M. Assi, and Wissam F. Fawaz (2012) 'Disruption-Tolerant Networking: A Comprehensive Survey on Recent Developments and Persisting Challenges', IEEE COMMUNICATIONS SURVEYS & TUTORIALS, 14(2), pp. 607-640.

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