Performance Study of Routing Schemes in Delay-Tolerant Networks

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Performance Study of Routing Schemes in
Delay-Tolerant Networks

• Chien-Shiu Lin, Wei-Shyh Chang, Ling-Jyh Chen,
  Cheng-Fu Chou, and Ting-Kai Huang

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Motivation

• Delay /Disruption Tolerant Networks (DTNS)
  attracted increasing attention recently.
• Whats the crucial factors for a successful
  routing algorithms in Delay/Disruption Tolerant
  Networks?

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Our contributions

• Analysis of several kinds of routing schemes
• Epidemic routing
• PROPHET routing
• NC routing
• Propose two enhancements for PROPHET
• Contact utilization (PROPHET_CU)
• Contact duration ratio (PROPHET_CD)

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Epidemic routing

• Store, carry and forward model
• Utilize redundancy to increase the success
  probability
• But,
• flooding overhead

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PROPHET routing

• Based on Epidemic Routing Scheme
• Use delivery predictability to reduce flooding
  overhead
• Delivery predictability
• Pinit an initialization constant
• Nodes that are often encountered have a high
  delivery predictability.

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PROPHET Enhancements (PROPHET_CU)

• The number of contacts vs. the duration of
  contact
• Contact Utilization (Prophet_CU)

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PROPHET Enhancements (PROPHET_CD)

• Super stars avoidance (load balance)
• Contact Duration Ratio( Prophet CD)

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Network Coding

• Use coding skill to increase success probability
• Apply Network Coding on the packet

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Simulation

• DTNSIM A Java-based simulator
• A Real-world wireless trace
• ZebraNet1
• ZebraNet2 (decreasing 30 contact durations)

ZebraNet1 ZebraNet2
Avg contact duration/pair/day(sec) 22,211 12,825
Avg of contacts/pair/day 2.06 2.06
Number of nodes 34 34
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Simulation Settings
Trace Name ZebraNet1, ZebraNet2
CBR Traffic (1 MB/msg) 1 msg/hour
Contact bandwidth 1 MB/s
H (hop count limit) 5
m(computation depth) 4
T (time interval) 2 day
Number of pairs 1, 10, 20, 30
Buffer size 400 MB
Simulation time 16 day
Pinit / ? / ? 0.75 / 0.98 / 0.25
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PROPHET vs. Enhanced PROPHET

• ZabraNet1

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PROPHET vs. Enhanced PROPHET
30 node pairs
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PROPHET vs. Enhanced PROPHET

• ZebraNet2

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Routing comparison
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Routing comparison
30 node pairs
10 node pairs
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Routing comparison various error rate
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Conclusion

• We propose enhancement schemes on PROPHET.
• Contact duration is an important factor
• We study several DTN routing schemes and suggest
  suitable network environment for each routing
  protocol.
• Epidemic routing is sensitive to network loading.
• NC has best delivery ration in congestion
  situation.
• NC routing is vulnerable in network with high
  error rate

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• Thank you