1. Sujit Dey Adaptive Applications for Wireless Information Technology Sujit Dey ECE Department University of California, San Diego dey@ece.ucsd.edu http://esdat.ucsd.edu

2. Sujit Dey Ubiquitous Mobile Information Technology Heterogeneous Network Configurations, Access Technologies, Data Services, and Network Appliances

3. Sujit Dey Applications & Data Services for the Communication Era Computing Era –Primary Resource: Computing –Paradox: Computing resources increased over years, but so did problem complexity –Solution: Efficient computing algorithms: minimize computation ops –Metrics: Runtime, space complexity Communication Era –Primary Resource: Bandwidth –Paradox: As bandwidth capabilities increase, so will new data-intense wireless services and number of users –Solution: Adaptive Applications: minimize data traffic –Metrics: Quality of data; Quality of service

4. Sujit Dey Our Approach: Adaptive Wireless Data The Internet Base Station Wireless Gateway Server Web Servers Configurable Handheld Client Browser Application Shaper Application Shaper Network Conditions Application Requirements Application Requirements Access Profile Client Characteristics

5. Sujit Dey Energy-Constrained Wireless Application Design : Motivation Start Breaking News Politics SportsEnter.Finance BN Headlines Politics Headlines Football Headlines Basketball Headlines Science Fin. Headlines Enter. Headlines Science Headlines BN Summary Politics Full Story Politics Summary Science Summary Weather Science Full Story Football Summary Football Full Story Basketball Summary Basketball Full Story Enter. Full Story Enter. Summary Fin. Summary Fin. Full Story 0.3 0.1 0.2 0.05 0.15 0.1 1 0.5 10.4 0.2 0.3 0.9 0.1 0.6 0.4 0.8 0.3 1.0 0.20.9 0.1 0.4 END 0.4 0.9 0.3 0.1 0.5

6. Sujit Dey Wireless Application Design : Energy Optimization Politics SportsEnter.Finance Politics Headlines Football Headlines Basketball Headlines Science Enter. Headlines Politics Full Story Science Full Story Football Summary Football Full Story Basketball Summary Basketball Full Story Enter. Full Story Enter. Summary Fin. Full Story 0.3 0.1 0.2 0.05 0.15 0.1 0.5 10.4 0.2 0.3 0.1 0.4 0.3 1.0 0.2 0.1 0.4 END 0.4 0.9 0.3 0.1 Breaking News with Summary Start & Weather Fin. Headlines & Summary 0.5 Politics Headlines Politics Full Story Headlines

7. Sujit Dey Wireless Applications : Energy Modeling & Optimization Goal : Develop energy modeling methodology for wireless application design exploration and optimize energy consumption Steps : Develop an energy model for handheld clients (PalmVII) using measurement based methodology Develop a generic energy estimation methodology for wireless applications

8. Sujit Dey Energy Model Encryption Connection Setup Connection Setup Transmission Decompression Decryption Reception Idling Time T T * Enc L R R / Comp R * Enc / Comp E(R,T,C,L,Enc,Comp) = C0C0 + C idle *L + C r *(C*R*Enc/Comp)+ + C t *(T*Enc) + C enc *T + C comp *R

9. Sujit Dey Validation of Energy Model Comparison of measured energy consumption with energy estimation using the proposed model – Based on average energy consumption over 10 accesses Energy Model : Sufficiently Accurate to drive application level energy optimization Application Measured Energy (J) Estimated Energy (J) % Error News Travel Personal 2.983 2.219 0.735 2.800 2.200 0.730 6.0 5.0 0.5

10. Sujit Dey Energy Aware Application Optimizations Start Breaking News Politics SportsEnter.Finance BN Headlines Politics Headlines Cricket Headlines Basketball Headlines Science Fin. Headlines Enter. Headlines Science Headlines BN Summary Politics Full Story Politics Summary Science Summary Weather Science Full Story Cricket Summary Cricket Full Story Basketball Summary Basketball Full Story Enter. Full Story Enter. Summary Fin. Summary Fin. Full Story 0.3 0.1 0.2 0.05 0.15 0.1 1 0.5 10.4 0.2 0.3 0.9 0.1 0.6 0.4 0.8 0.3 1.0 0.20.9 0.1 0.4 END 0.4 0.9 0.3 0.1 Fin. Headlines & Summary 0.5 Breaking News with Summary Aggregation Headlines Deletion Start & Weather Migration Politics Headlines Politics Full Story Splitting

11. Sujit Dey Exploration Methodology for Energy- Efficient Web Application Design Probabilistic Web Flow Graph Transaction Generator Client Energy Model Energy Estimator Usage Profile Web Design N1 N2 N3 N4 N6 N5 Access Probability Web Page (b_tran, b_recv, priority)

12. Sujit Dey Future Efforts The Internet Base Station Wireless Gateway Server Web Servers Configurable Handheld Client Browser Application Shaper Application Shaper Network Conditions Application Requirements Application Requirements Access Profile Client Characteristics WLAN WCDMA

13. Sujit Dey Network Aware Application Adaptation Factors influencing network environment –Different network technologies (WLAN,WCDMA,HDR) –Time varying bandwidth inside a network technology Example : Rate Adaptation in WCDMA/HDR –User Mobility –Network Load Effect of the above factors on applications –Energy –Latency –Error Quality Objective: Adapt applications according to the current network environment to minimize energy consumption, latency of communication, and error quality.

14. Sujit Dey Considering Network Effects on Energy Extend energy model to incorporate network effects –simulation based Network Parameters –Signal Strength determines “transmission power level” no of re-transmissions –Network Load idle period Energy Model Energy = T T (SS) * ( E(R,T,C,L,Enc,Comp) + T R (SS) ) + I(Network Load) T T (SS) & T R (SS) : Table lookups based on signal strength I (Network Load) : Table lookup based on network load

15. Sujit Dey Test-bed Environment

16. Sujit Dey Conclusion We developed an energy model and optimization techniques to adapt application to conserve energy We are currently working to develop network aware adaptation techniques We want to develop a test-bed environment to demonstrate and validate our ideas

17. Sujit Dey Network-Aware Application Adaptation Idea : To deliver information to users transparent of network conditions Means –Server : Re-organization of content –Techniques : Filtering, Splitting, Clustering »Step 1 : Filter out information which may not be useful »Step 2 : Split Information into atoms of information »Step 3 : Combine the atoms of information based on history information –Issues : » Temporary Storage of transformation » Maintenance of connection state information –Client : Pre-fetching & Presentation