MobiClique: Middleware for Mobile Social Networking

1. WOSN’09: 2nd ACM SIGCOMM Workshop on Online Social Networking 17.08.2009, Barcelona, Spain MobiClique: Middleware for Mobile Social Networking Anna-Kaisa Pietilainen (Thomson), with Earl Oliver (University of Waterloo), Jason LeBrun (UC Davis), George Varghese (UCSD), Christophe Diot (Thomson)

2. Mobile Social Networking? • Plenty of resources on smartphones • Content can be created and stored • Many contact opportunities using various radio interfaces • Limitations of current social networking services • Closed or limited access and proprietary data formats and APIs • Do not take advantage of real social contacts and mobility • Get the best of both worlds ! • Create ad-hoc communities and social networks • Exchange content with friends while on the move

3. Outline • MobiClique Design Principles • System Architecture • User Trials and Performance • Conclusion and Future Work

4. MobiClique Design Principles • Leverage existing online social networks • Avoid creating ‘yet-another-service’ • Decentralized, ad hoc operation • Free, no third parties involved, context & mobility aware • Build and maintain an ad hoc social network and connections • Social networking (i.e. meet new people and communities) • Content sharing and messaging over multiple hops in the social network overlay • Provide an open API for mobile social and opportunistic networking applications

5. System Overview

6. Middleware Operation on Mobiles • Neighborhood discovery • Bluetooth device discovery, broadcast beacons over WiFi • User identification • Social profile exchange • Data exchange • Store-carry-forward style communication • Unicast messages forwarded over the friendship graph or upon direct contact • Multicast messages flooded within the interest group • TTL defined using an absolute timestamp and/or hop count

7. The Applications • Mobile social networking • Asynchronous messaging • Epidemic newsgroups • New: ad hoc voting

8. Prototype Implementation • Builds on the Haggle architecture prototype • Data-centric opportunistic communications • Windows Mobile platform • Programmed in C++ and C# • Bluetooth connectivity • Reasonable battery life in normal use (charge daily) • Discovery performed every 2 minutes for 10.24s • RFCOMM device to device communication links • Social profile initialization using Facebook • Simple desktop application to setup the MobiClique social profile

9. Experimental Setup • HTC s620 Windows Mobile Smartphone • 200 MHz TI processor • 64MB RAM, 128MB ROM, MicroSD slot • Bluetooth v1.2

10. Contact Opportunities (CoNEXT’07) 600 500 Any Participant 400 Shared Interest 300 200 49% 100 Friend 25% 0 Day 1 8:00 20:00 Day 2 8:00 Day 3 8:00 20:00 20:00 Day 4 8:00

11. Bluetooth Connectivity (CoNEXT’07) 10 100% 8 Avg success rate 50% Participant 6 Count 4 Success rate 2 Connected 0 14:30 20:30 2:30 8:30 14:30 8:30

12. Social Network Evolution (CoNEXT’07) Avg. degree 9,18 Avg. degree 5,11 Final Friendship Graph Initial Friendship Graph

13. Conclusion and Future Work • MobiClique creates and maintains an ad hoc mobile social network for opportunistic content dissemination • Two user trials to collect unique 3-day traces combining user’s social behavior and interaction, contact opportunities and opportunistic messaging • On going and future work • Lab test to improve system parameters • Improve the prototype: connectivity, forwarding, resource management, security • Publish the source code and the collected traces

14. This is NOT the end …. Join the MobiClique SIGCOMM 2009 experiment! Catch one of us or come to the MobiClique desk near the registration area Thanks!