Waldir Moreira, Manuel de Souza, Paulo Mendes, and Susana Sargento waldir.junior@ulusofona.pt

July 9th, 201211th International Conference on Ad-Hoc Networks and Wireless (ADHOC-NOW 2012)

Belgrade, Serbia

Study on the Effect of Network Dynamics on Opportunistic Routing

2

Agenda

• Introduction

• Motivation

• Our Approach

• Evaluation

• Results

• Conclusions and Future Work

3

Introduction

• Powerful devices

• Spontaneous networks

• Opportunistic contacts

- Intermittent connectivity

• Many routing solutions

- epidemic, encounter history, social aspects ...

• Resulting proximity graphs are unstable

• Dynamism of users’ daily life routines

• Study the effect of network dynamics

4

Motivation

• To consider the oscillations of social interactions (influenced by daily routines)

• Two utility functions

- Time-Evolving Contact Duration (TECD)

- TECD Importance (TECDi)

5

Our Approach

6

Our Approach

7

Our Approach: TECD

A Bw(B,x)

A B

If Mx Buffer(B) and w(B,x) > w(A,x)

Mx

(1)

(2)

8

Our Approach: TECDi

AI(B)

AMx

(1)

(2)

B

B

If Mx Buffer(B) and I(B) > I(A)

9

EvaluationParameters Values

Simulator Opportunistic Network Environment (ONE)

Routing Proposals

Contact-based vs Social-based

PRoPHET, Epidemic, TECD Bubble Rap, Rank, TECDi

Heterogeneous Mobility

1036800 sec

150 (people/vehicles)

Working Day, Bus, Shortest Path Map Based

Bluetooth (250 kbps / 10 m) Wi-Fi (Bus: 11 Mbps / 250 m)

2 MB

24 hours and Unlimited

1 – 100 kB

6000

5 (Bubble Rap)

700 sec (Bubble Rap)

0.8 (Rank)

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Results

- TECD has a gain of: PROPHET: 16.17% (24) and 18.41% (Un) Epidemic: 23.77% (24) and 23.26% (Un)

- PROPHET suffers occasional finite loops => use transmission opportunities

- Epidemic quickly exhausts buffer space => 2 MB per node

- TECDi has a gain of: Rank: 6.06% (24) and 4.88% (Un) Bubble Rap: 12% (24) and -9% (Un)

- Bubble Rap has more time for communities => increased delivery capability

- Rank doesn't consider social levels => important nodes, weak ties

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Results

- TECD with less replicas (57.37 and 121.30): PROPHET: 272.35 (24) and 247.11 (Un) Epidemic: 454.12 (24) and 535.04 (Un)

- TECD advantage decreases with unlimited => messages live longer in the system

- PROPHET and Epidemic => buffer limitations

- TECDi with less replicas (266.12 and 363.02): Rank: 302.05 (24) and 418.21 (Un) Bubble Rap: 559.69 (24) and 495.69 (Un)

- TECDi reduces the potential next hops => important nodes, strong ties

- Bubble Rap has the highest costs => global centrality

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Results

- Latency increases with TTL

- Lack of a stale data removal mechanism => affects all solutions

- Unlimited TTL => more messages, increase in delivery probability

- TECDi replicates based on importance => top-ranked nodes, more time to reach destination

- Bubble Rap high latency with 24-hour TTL => formation of communities => finding higher centrality nodes influences overall latency

• Dynamism positive affects forwarding decisions

• TECD performs better than TECDi => node importance

• "Opportunistic Routing Based on Daily Routines," in Proc. of the 6th IEEE WoWMoM Workshop AOC, SFO, USA, June, 2012

• Internet-Draft (draft-moreira-dlife-00)DTNRG Meeting, Vancouver, July 2012

• Next steps

13

Conclusions andFuture Work

Information-Centric version of dLife

To FCT for financial support via PhD grant (SFRH/BD/62761/2009) and UCR project (PTDC/EEA-TEL/103637/2008)

14

Acknowledgements

Waldir Moreira, Manuel de Souza, Paulo Mendes, and Susana Sargento waldir.junior@ulusofona.pt

July 9th, 201211th International Conference on Ad-Hoc Networks and Wireless (ADHOC-NOW 2012)

Belgrade, Serbia

Study on the Effect of Network Dynamics on Opportunistic Routing