行動多媒體串流 之省電應用軟體 隊伍名稱：EMCLAB@CITI 參賽單位：中央研究院 資訊科技創新研究中心 參賽者 ：謝承剛、林均翰、鄭志川、修丕承

2011電信創新應用大賽 行動應用社會組

Motivation • Mobile applications and

services are having a profound effect on people's lifestyles.

• The energy consumption of mobile devices is a major challenge in sustaining the applications and services.

• Cisco Forecast: Video streams will account for 66% of mobile data traffic by 2014.

2

Dynamic Backlight Scaling • The screen backlight consumes

most of the energy for mobile streaming applications.

• Dynamic backlight scaling is deemed a promising technical solution.

• When to dim the backlight to which level? • Video distortion • Hardware/software limitation • User perception • Etc.

• Our IEEE/ACM ISLPED’11 paper has the answer!

3

Dynamic Backlight Scaling

Power distribution on HTC Desire when browsing videos on YouTube

Android Software • Without changing their user

preferences • Display with YouTube

• Display with our software

• Functionality

• Turn on/off backlight scaling • Show/hide backlight scaling • Compute energy saved in joule

and percentage • Pause, fast forward/backward

4

Demonstration – HTC Desire

5

Approach validation

Performance evaluation

Case Studies

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Case studies

Experimental results

Possible Scenario I: Video Content Provider

• Backlight scaling information embedded in videos • Expected Profits

• Less energy consumption for watching the same video • More attractive to mobile customers than other competitors

7

Video Stream Streaming Server

Mobile Device

• Backlight scaling information provided with videos • Expected Profits

• 1million users x 30 dollars/month = 30 million dollars/month • Facility rental + maintenance cost ≈ 2 million dollars/month • Net profit ≈ 28 million dollars/month

Possible Scenario II: Energy-Saving Service Provider

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Video Stream

Backlight File Backlight Server

Streaming Server

Mobile Device

Conclusion • Mobile users are addicted to media applications, such as

YouTube and IPTV, while energy consumption is a major challenge in sustaining the applications.

• We propose a dynamic-backlight-scaling technology, develop it as Android software, and discuss potential business models to exercise the technology.

• We have released our software on the Hami Apps so that people with Android phones can benefit from our technology. • With the software installed, an HTC Desire mobile phone can save

18-31% backlight energy when browsing videos on YouTube.

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We are the Research Center for IT Innovation

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