Only first slide is Chinese.

1. 2011電信創新應用大賽
行動應用社會組
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

2. 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

3. Dynamic Backlight Scaling
• The screen backlight consumes
most of the energy for mobile
streaming applications.
• Dynamic backlight scaling is
deemed a promising technical
solution. Power distribution on HTC Desire when
• When to dim the backlight to browsing videos on YouTube
which level?
• Video distortion
• Hardware/software limitation
• User perception
• Etc. 3
• Our IEEE/ACM ISLPED’11
Dynamic Backlight Scaling
paper has the answer!

4. 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

5. Demonstration – HTC Desire
Approach validation
Performance evaluation
5

6. Case Studies
Case studies
Experimental
results
6

7. Possible Scenario I:
Video Content Provider
Video Stream
Streaming Server
Mobile Device
• 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

8. Possible Scenario II:
Energy-Saving Service Provider
Video Stream
Streaming Server
Backlight File
Mobile Device Backlight Server
• Backlight scaling information provided with videos
• Expected Profits
• 1million users x 30 dollars/month = 30 million dollars/month 8
• Facility rental + maintenance cost ≈ 2 million dollars/month
• Net profit ≈ 28 million dollars/month

9. 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. 9

10. We are the Research Center for IT Innovation
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