DelayTolerant Mobile Adhoc Networks

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Delay-Tolerant Mobile Ad-hoc Networks

• Network Research Lab
• UCLA

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DTN Background
1 satellite
2 dialup
Receive data from Ann
Send data to Brandy
3 memory stick on motorcycle
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DTN Background

• DTN new network architecture for scenarios with
  intermittent connectivity
• Interplanetary communications,
• Communications between remote villages (example
  on previous slide),
• Communications with mobile users, etc.
• Common DTN characteristics
• Data is aggregated into bundles at intermediate
  node where connection breaks up.
• Bundles await the re-establishment of
  connectivity
• Bundles are sent in steps from one disconnect
  point to the next until they reach destination
  (rather than using a single end-to-end file
  transfer).

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Ad-hoc Storage Overlay System (ASOS)

• In MANETs (Mobile AdHoc Networks), connectivity
  is often disrupted due to mobility, interference,
  failures, etc.
• ASOS Ad-hoc Storage Overlay System
• Proposed DTN approach for MANETs
• Peer-to-peer model
• Data are transmitted end-to-end directly, if a
  path exists.
• Otherwise, data are stored in the overlay in a
  redundant and distributed fashion.

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ASOS Example
4 ASOS data delivery
D
2 Network partitioning
ASOS overlay
1 Conventional end-to-end connection
3 Undeliverable data replicated to reachable
ASOS peers
S
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Performance Evaluation Vehicle Scenario

• ASOS implemented in QualNet
• Virtual Track (VT) mobility model
• Battlefield scenario
• 7 switch stations
• 4 tank platoons, with 5 tanks each
• 5 HUMVEEs
• 5 relay stations
• Traffic
• CBR, 5 sources to one destination (command post),
  all moving

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Instantaneous Throughput

• Conventional scheme
• instantaneous throughput always below input rate.
• ASOS
• Instantaneous throughput may go above input.
• Reason stored data is transmitted later when
  connectivity improves.

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Delivery Ratio

• Overall, at the end of the data transfer, ASOS
  manages to deliver twice as much data as the
  conventional scheme

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Work in progress DTN Backbone

• MB nodes used for storage
• Thin BB links vs high speed ground links

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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone
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Delay Tolerant Mobile Backbone