1. Web Surfing on the Move: Needs, Opportunities, and Challenges Ling-Jyh Chen (cclljj@iis.sinica.edu.tw) Institute of Information Science Academia Sinica, Taiwan

2. Outline of the Talk 1.Why do we need it? 2.How to do it? 3.What can we do further?

3. Outline of the Talk 1.Why do we need it? 2.How to do it? 3.What can we do further?

4. Why do we need Mobile Web Surfing? Fact 1: Web is the life !

5. Why do we need Mobile Web Surfing? Fact 1: Web is the life !

6. Why do we need Mobile Web Surfing? Fact 1: Web is the life ! Fact 2: Wireless is everywhere !

7. Why do we need Mobile Web Surfing? Fact 1: Web is the life ! Fact 2: Wireless is everywhere ! Fact 3: We need mobility!

8. Why do we need Mobile Web Surfing? Fact 1: Web is the life ! Fact 2: Wireless is everywhere ! Fact 3: We need mobility! Fact 4: Storage is cheap and vast!

9. Why do we need Mobile Web Surfing? Fact 1: Web is the life ! Fact 2: Wireless is everywhere ! Fact 3: We need mobility! Fact 4: Storage is cheap and vast! Q: Why do we NOT need it?

10. Outline of the Talk 1.Why do we need it? 2.How to do it? 3.What can we do further?

11. Previous Solutions 1.Offline-based approaches –wget –wwwoffle –Offline browsing (e.g., IE, Firefox, etc.)

12. Previous Solutions 1.Offline-based approaches –wget –wwwoffle –Offline browsing 2.Cache-based approaches –Push based (Aalto ‘04, Costa-Montenegro ‘02, Spangler ‘97) –Pull based (Jiang ’98, Jiang ’98, Padmanabhan ‘96)

13. Previous Solutions 1.Offline-based approaches –wget –wwwoffle –Offline browsing 2.Cache-based approaches –Push based (Aalto ‘04, Costa-Montenegro ‘02, Spangler ‘97) –Pull based (Jiang ’98, Jiang ’98, Padmanabhan ‘96) 3.Infostation-based approaches –Mobile Hotspots (Ho ‘04) –Thedu (Balasubramanian ‘07)

14. Previous Solutions Well, the problems of these solutions are –(1) needs end users to manually dump web sites to their handhelds. –(1&2) need tremendous amount of storage space. –(3) needs dedicated servers. –(1&2&3) only allow Internet-capable users to access web documents.

15. Previous Solutions Well, the problems of these solutions are –(1) needs end users to manually dump web sites to their handhelds. –(1&2) need tremendous amount of storage space. –(3) needs dedicated servers. –(1&2&3) only allow Internet-capable users to access web documents. An ideal/better solution should 1.Reduce storage/power consumption for handhelds 2.Allow Internet-incapable users to surf webs

16. Our Solution: CIA Collaborative Internet Access (CIA) collaborationlocal wireless bandwidth)not –Idea: enable the mobiles to access the Internet, via collaboration (i.e., using local wireless bandwidth), even if he/she is not directly connected to the Internet.

17. CIA Components Direct ForwardingDirect Forwarding: download data from gateway nodes

18. CIA Components Direct ForwardingDirect Forwarding: download data from gateway nodes Indirect ForwardingIndirect Forwarding: download data from non-gateway nodes

19. CIA Components Direct ForwardingDirect Forwarding: download data from gateway nodes Indirect ForwardingIndirect Forwarding: download data from non-gateway nodes Collaborative ForwardingCollaborative Forwarding: download/forward data to other relays –Probabilistic Forwarding –Layered Multiple Description Coding

20. CIA Flowchart

21. Collaborative Forwarding Probabilistic Forwarding –Decide whether to forward a message to a newly encountered node based on the delivery probability estimate.

22. Collaborative Forwarding Probabilistic Forwarding –Decide whether to forward a message to a newly encountered node based on the delivery probability estimate. –One-hop delivery probability –Two-hop delivery probability

23. Collaborative Forwarding Layered Multiple Description Coding (LMDC) –Layered coding

24. Collaborative Forwarding Layered Multiple Description Coding (LMDC) –Layered coding

25. Collaborative Forwarding Layered Multiple Description Coding (LMDC) –Layered coding –Unequal erasure coding

26. CIA Evaluation We implemented CIA in DTNSIM. Network traffic: based on the log of NTU proxy server in the period 2006/4 to 2006/9 Network scenarios: based on mobility traces

27. CIA Evaluation Results 5% are GN iMote IBMUCSD

28. CIA Evaluation Results 10% are GN iMote IBMUCSD

29. CIA Evaluation Results 15% are GN iMote IBMUCSD

30. Outline of the Talk 1.Why do we need it? 2.How to do it? 3.What can we do further?

31. Remaining Issues Buffer Management

32. Remaining Issues Buffer Management Overhead –Explicit ACK or Passive Cure –Adaptive Erasure/Network Coding

33. Remaining Issues Buffer Management Overhead Versioning

34. Remaining Issues Buffer Management Overhead Versioning Information Security –Identity-Based Cryptography (IBC) (?)

35. Remaining Issues Buffer Management Overhead Versioning Information Security System Reliability (e.g., free-riders, blackholes, wormholes)

36. Where are we? Designed CIA for Mobile Web Surfing Implemented CIA in DTNSIM Evaluated CIA using realistic network scenarios Work in progress –Implement CIA on handhelds –Experiments and analysis

37. Summary of the talk With emerging mobile and wireless network applications, Mobile Web Surfing has become highly desired. We presented a Collaborative Internet Access approach, and evaluated CIA using realistic network scenarios. We showed that CIA can greatly improve mobile web surfing via exploiting network mobility. Challenges with plenty of opportunities!

38. Thanks! http://www.iis.sinica.edu.tw/~cclljj/ http://nrl.iis.sinica.edu.tw/