1. A Study on Mobile P2P Systems Hongyu Li

2. Outline  Introduction  Characteristics of P2P  Architecture  Mobile P2P Applications  Conclusion

3. Introduction  P2P content downloading activity becomes more and more popular.  Mobile computing has emerged as one of the leading technologies in the 21st century.  Combination of P2P systems and ad-hoc networks allows for the creation of highly dynamic, self-organizing, mobile P2P systems.

4. Introduction  What is Mobile P2P ”A type of network in which mobile nodes can connect to other nodes via short- range wireless technologies such as IEEE 802.11, Bluetooth, or Ultra Wide Band (UWB) when needed.”

5. Characteristics  Fully decentralized : all peers are equally important within the network.  Highly dynamic, unpredictable : mobile hosts move frequently and independently of one another.  Self-organizing : a mobile P2P system constantly adjusts itself by discovering new communication links.

6. Characteristics  Limited peer-to-peer communication throughput : constrained by the wireless bandwidth, the channel contention, and the limited connection time.  Need incentive for both information supplier and information propagators : mobile peer-to-peer networks heavily relies on cooperation among users.

7. Architecture Most common P2P models:  Centralized model – “hybrid P2P”  Decentralized but unstructured model – “pure P2P”  Decentralized and structured model  Semi-Centralized model

8. Architecture  The eDonkey approach (Still ongoing)

9. Architecture Different routing Protocols:  Broadcast over broadcast: only works temporarily for small MANET.  Broadcast : not suitable for large networks.  DHT over broadcast: complex to implement.

10. Mobile P2P Applications  Proem First documented system for mobile P2P. an middleware platform that provides a complete solution for developing and deploying P2P applications for mobile ad-hoc networks. http://wearables.cs.uoregon.edu/proem

11. Mobile P2P Applications  Proem

12. Mobile P2P Applications  JXME a light version of JXTA for mobile devices. provide JXTA compatible functionality’s on contained devices using CLDC and MIDP. JXME uses relays to connect lightweight mobile peers to the rest of the JXTA network.

13. Mobile P2P Applications  JXME http://jxme.jxta.org

14. Conclusion  Challenges Network Availability Mobile device limitation Peer and Resource Discovery Data Sharing and Synchronization Security threats Privacy

15. Conclusion  Future The development of mobile P2P system is still in its early stage. With technology development, we could expect P2P services to be offered by mobile operators in the next few years.

16. Thank You !