region topology aware routing for dtn
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Region Topology Aware Routing for DTN. AsiaFI School on Mobile and Wireless Networks 2009. 01. 15 Presented by Dukhyun Chang ([email protected]). Contents. Introduction Proposed Algorithm : RTAR Simulation Results Conclusion. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Region Topology Aware Routing Region Topology Aware Routing for DTNfor DTN
AsiaFI School on Mobile and Wireless Networks2009. 01. 15
Presented by Dukhyun Chang ([email protected])
ContentsContents
IntroductionProposed Algorithm : RTARSimulation ResultsConclusion
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IntroductionIntroduction
Many routing protocols for DTNs are based on Flooding– Epidemic Routing, PRoPHET, Spray and Wait …– Epidemic Routing
• Transfers messages that the encounter doesn’t have• Very high message overhead
– Spray And Wait• Limits the number of message copies
– L : max # of message copies• Consists of Spray phase and Wait phase
– PRoPHET• Probabilistic Routing Protocol using History of Encounters and
Transitivity• Uses delivery predictability
These are not proper when a network is divided into some groups
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IntroductionIntroduction
In our proposal– Exploits network topology and mobility information
Network Topology– The networks consist of
sub networks (“regions”)– Nodes move within regions
or between regions
We propose– Region Topology Aware Routing (RTAR) for DTN
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RTAR: Assumptions and Data RTAR: Assumptions and Data StructuresStructures
Some assumptions – A node doesn’t know
• Location of destination node• What regions are exists
– A node knows• Region ID where I am located• Which region contacted node goes for
Data structures – Region vector: detected region information– Table mapping (region ID, # of tokens) to each
messages
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RTAR: Basic OperationsRTAR: Basic Operations
Controls the # of message relays with the region and mobility information
– A source creates the limit of # of message relays (token) for known regions
– All nodes having tokens handover tokens• Half of tokens for current region id to contacted
intra-region nodes• All of tokens for other region to a first
contacted node which goes for that region
– Creates tokens for newly found regions
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RTAR Example (1/2)RTAR Example (1/2)
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Region 1 Region 2
B
C
H
E
M(R1:4,R2:4)
A
D
Region 3
F
G
I
Region 1 Region 2
C
F
E
M(R1:2,R2:4)
AM(R1:2)
B
D
H
Region 3
I
Region 1 Region 2
F
E
M(R1:2)
A
M(R1:1)
M(R1:1)
M(R2:4)
B
C
D
G
H
Region 3
G
I
Region 1 Region 2
FM(R1:2)
A
M(R2:2)
M(R1:1)
M(R1:1)
B
C
E
M(R2:2)
D
H
Region 3
G
I
Create messageAllocate tokens
Spread message with in region
Hand over a half tokens
Hand over all tokens
Message is spread to other region
RTAR Example (2/2)RTAR Example (2/2)
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M(R3:1)
Region 1 Region 2
FM(R1:2)
A
M(R2:2,
R3:2)
M(R1:1)
M(R1:1)
B
C
E
M(R2:2)
D
H
Region 3
G
I
Region 1 Region 2
FM(R1:2)
A
M(R2:2)
M(R1:1)
M(R1:1)
B
C
E
M(R2:2)
D
H
Region 3
IM(R3:2)
G
Region 1 Region 2
FM(R1:2)
A
M(R2:2)
M(R1:1)
M(R1:1)
B
C
E
M(R2:2)
D
Region 3
I
M(R3:1)
G
Region 1 Region 2
FM(R1:2)
A
M(R2:2)
M(R1:1)
M(R1:1)
B
C
E
M(R2:2)
D
Region 3
HM(R3:
1)
G
M(R3:1)
H
I
Detect new regionfrom region vector
Allocate new tokens
Hand over all tokens
Message is spread to other region
that A doesn’t know
Message is arrivedto the destination
Simulation SettingSimulation Setting
Simulator: Opportunistic Network Environment (ONE)
Regions– Unit Region Size: 1 X 1km2
– 4 Regions in the networkNodes
– # of nodes in each region : 50
Packets– Each node sends 6 packet for 6 hours– Packet size: 100kbytes
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Intra-region node Inter-region node
Tx range 10m 30m
Tx speed 256kbps 512kbps
Speed 0.5 ~ 5m/s 10m/s
Buffer size
Unlimited or 20MB 2GB
Simulation Results (Limited Buffer)Simulation Results (Limited Buffer)
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0
0.2
0.4
0.6
0.8
1
0 5 10 15
Rati
o
Time (h)
Total Delivery Ratio
epiprosnw(L=16)snw(L=48)rta
messages) created all of (#
n)destinatio the tomessages delivered of (# ratioDelivery
Simulation Results (Limited Buffer)Simulation Results (Limited Buffer)
0
50
100
150
200
250
300
0 5 10 15
Ove
rhea
d
Time (h)
Total Overhead
epiprosnw(L=16)snw(L=48)rta
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messages) created all of (#
messages) delivered of (# - messages) relayed of (# ratio Overhead
Simulation Results (Unlimited Simulation Results (Unlimited Buffer)Buffer)
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messages) created all of (#
n)destinatio the tomessages delivered of (# ratioDelivery
0
0.2
0.4
0.6
0.8
1
0 5 10 15
Rati
o
Time (h)
Total Delivery Ratio
epiprosnw(L=16)snw(L=48)rta
0
0.2
0.4
0.6
0.8
1
0 5 10 15
Rati
o
Time (h)
Delivery Ratio within Regions
epiprosnw(L=16)snw(L=48)rta
0
0.2
0.4
0.6
0.8
1
0 5 10 15Ra
tio
Time (h)
Delivery Ratio Between Regions
epiprosnw(L=16)snw(L=48)rta
Simulation Results (Unlimited Simulation Results (Unlimited Buffer)Buffer)
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messages) created all of (#
messages) delivered of (# - messages) relayed of (# ratio Overhead
0
50
100
150
200
250
0 5 10 15
Ove
rhea
d
Time (h)
Total Overhead
epiprosnw(L=16)snw(L=48)rta
ConclusionConclusion
Region Topology Aware Routing protocol for DTN
– Distributing messages achieves high delivery probability and low overhead using region information and mobility information
Future works– Analyzing appropriate number of tokens
when all regions are known– Designing the mechanism controlling token
numbers dynamically– And so on.
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Q&A
15/14
Message RelayMessage Relay
Add new tokens for regions not shown in messages
16/13
R2
R1 R3R1 4
R2 4
R1 0
R2 4
R3 4
R1 0
R2 4
R1 0
R2 0
R3 4