Web Surfing on the Move: Needs, Opportunities, and Challenges Ling-Jyh Chen ([email protected]) Institute of Information Science Academia Sinica,

Web Surfing on the Move: Web Surfing on the Move: Needs, Opportunities, and Needs, Opportunities, and

ChallengesChallenges

Ling-Jyh Chen ([email protected])Institute of Information Science

Academia Sinica, Taiwan

Outline of the TalkOutline of the Talk

1. Why do we need it?

2. How to do it?

3. What can we do further?


1.1. Why do we need it?Why do we need it?

2. How to do it?


Why do we need Mobile Web Why do we need Mobile Web Surfing?Surfing?

• Fact 1: Web is the life !


• Fact 1: Web is the life !


• Fact 1: Web is the life !• Fact 2: Wireless is everywhere !


• Fact 1: Web is the life !• Fact 2: Wireless is everywhere !• Fact 3: We need mobility!


• Fact 1: Web is the life !• Fact 2: Wireless is everywhere !• Fact 3: We need mobility!• Fact 4: Storage is cheap and vast!


• 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?



2.2. How to do it?How to do it?


Previous SolutionsPrevious Solutions

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


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)


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)


• 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.


• 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 should1. Reduce storage/power consumption for handhelds2. Allow Internet-incapable users to surf webs

Our Solution: CIAOur Solution: CIA

• Collaborative Internet Access (CIA)– Idea: enable the mobiles to access the

Internet, via collaborationcollaboration (i.e., using local wireless bandwidth)local wireless bandwidth), even if he/she is notnot directly connected to the Internet.

CIA ComponentsCIA Components

• Direct ForwardingDirect Forwarding: download data from gateway nodes



• Indirect ForwardingIndirect Forwarding: download data from non-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

CIA FlowchartCIA Flowchart

Collaborative ForwardingCollaborative Forwarding

• Probabilistic Forwarding– Decide whether to forward a message to a

newly encountered node based on the delivery probability estimate.


• 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


• Layered Multiple Description Coding (LMDC)– Layered coding


• Layered Multiple Description Coding (LMDC)– Layered coding


• Layered Multiple Description Coding (LMDC)– Layered coding– Unequal erasure coding

CIA EvaluationCIA 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

CIA Evaluation ResultsCIA Evaluation Results

• 5% are GNiMoteiMote

IBMIBMUCSDUCSD



IBMIBMUCSDUCSD



IBMIBMUCSDUCSD



2. How to do it?

3.3. What can we do further?What can we do further?

Remaining IssuesRemaining Issues

• Buffer Management


• Buffer Management• Overhead

– Explicit ACK or Passive Cure– Adaptive Erasure/Network Coding


• Buffer Management• Overhead• Versioning


• Buffer Management• Overhead• Versioning• Information Security

– Identity-Based Cryptography (IBC) (?)


• Buffer Management• Overhead• Versioning• Information Security• System Reliability (e.g., free-riders,

blackholes, wormholes)

Where are we?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

Summary of the talkSummary 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!

Thanks!Thanks!

http://www.iis.sinica.edu.tw/~cclljj/

http://nrl.iis.sinica.edu.tw/

Documents

Web Surfing on the Move: Needs, Opportunities, and Challenges Ling-Jyh Chen ([email protected]) Institute of Information Science Academia Sinica,