SelfSelfSelfSelf----Adaptive Battery and Context Aware Mobile Adaptive Battery and Context Aware Mobile Adaptive Battery and Context Aware Mobile Adaptive Battery and Context Aware Mobile Application DevelopmentApplication DevelopmentApplication DevelopmentApplication Development

Soumya Kanti Datta

Research Engineer, EURECOM, France

Email: soumya-kanti.datta@eurecom.fr

10101010thththth IIIInternational Wireless Communicationnternational Wireless Communicationnternational Wireless Communicationnternational Wireless Communication and Mobile and Mobile and Mobile and Mobile

Computing Conference (IWCMCComputing Conference (IWCMCComputing Conference (IWCMCComputing Conference (IWCMC----2014)2014)2014)2014)

ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Result

• Conclusion

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 2

IntroductionIntroductionIntroductionIntroduction

• High power consumption

– at hardware resources

– By mobile applications

• Battery – a bottleneck for mobile devices and

applications

• Developed ‘Power Monitor’ to understand

– Usage patterns of smart devices

– How applications limit the battery life

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ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Result

• Conclusion

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 4

Brightness Level in Mobile DevicesBrightness Level in Mobile DevicesBrightness Level in Mobile DevicesBrightness Level in Mobile Devices

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 5

95

24

127

38

20

155

95

107

255 255

102

130

79

10

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135

255

125

65

255

96

179

63

144

30 34 30

107102

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Bri

gh

tne

ss

User No.

Brightness Level in Smart Devices

Energy Consumption at HardwareEnergy Consumption at HardwareEnergy Consumption at HardwareEnergy Consumption at Hardware

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Battery Consumption at Network InterfacesBattery Consumption at Network InterfacesBattery Consumption at Network InterfacesBattery Consumption at Network Interfaces

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Network Interface Battery Consumption (mA)

Active mode Idle mode

EDGE 300 5

3G 225 2.5 – 3

Wi-Fi 330 12 - 15

Network Network Network Network Usage of UsersUsage of UsersUsage of UsersUsage of Users

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0

50

100

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1 5 9 13 17 21 25 29

Tra

ffic

User

Total Network Traffic per Day (MB)

Upload

Downld

Lessons LearntLessons LearntLessons LearntLessons Learnt

• Applications keep on consuming power even though battery level is low and status is discharging.

• Many users of the smart devices do not modify the settings so that hardware elements spend less power.

• Thus– Applications should be self-adaptive to react to

battery level, status, context etc.

– Dynamically change the device settings to activate low-power mode

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ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Result

• Conclusion

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 10

SelfSelfSelfSelf----Adaptive FrameworkAdaptive FrameworkAdaptive FrameworkAdaptive Framework

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Battery and Context MonitorBattery and Context MonitorBattery and Context MonitorBattery and Context Monitor

• Battery monitor

– Battery level, status (AC/USB charging or

discharging)

• Context monitor

– Location (home, office, abroad)

• Statistics

– Battery charging pattern by correlating status

– Location

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Analyser EngineAnalyser EngineAnalyser EngineAnalyser Engine

• Examines

– Current battery level (B) , status (S), occurrence of

next charging opportunity (C) and location (L)

• Triggers one of these profiles

– Light self-adaption

– Medium self-adaption

– Strong self-adaption

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SelfSelfSelfSelf----Adaptive FeaturesAdaptive FeaturesAdaptive FeaturesAdaptive Features

• Hardware resource adaption

– Minimize brightness, turn off GPS

• Software resource adaption

– Use network to get location not GPS

• User feature adaption

– Turn-off secondary features in an application

• Additional optimization

– Distribute CPU intensive tasks

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ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Result

• Conclusion

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 15

Prototype ImplementationPrototype ImplementationPrototype ImplementationPrototype Implementation

• Two Android apps are developed– One with self-adaptive features and another without that.

• The functionalities are– Display several texts in the screen with default brightness

level being 200.

– Stream videos from a server and enabling background services to download and upload images, video and text files to a server. These are the primary functionalities of the application.

– Display location in a map using both GPS and network based locations to compare and determine the best location. This is a secondary feature in the application.

– Show in-app advertisements.

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Condition for No SelfCondition for No SelfCondition for No SelfCondition for No Self----AdaptionAdaptionAdaptionAdaption

• Battery level lies within 76-100

– 76 < B < 100

• Battery status can be either discharging or charging

– S == discharging or S == charging

• Irrespective of the occurrence of charging opportunity and location information

– C == Anything

– L == Anything

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Conditions for Light SelfConditions for Light SelfConditions for Light SelfConditions for Light Self----AdaptionAdaptionAdaptionAdaption

• Triggered when one of the following is true

• Condition 1

– (51<B<75) and (S == discharging) and (C==anything) and

(L==anything)

• Condition 2

– (11<B<50) and (S == AC charging) and (C==anything) and

(L==anything)

• Condition 3

– (11<B<50) and (S == discharging) and (11<C<30) and

(L!=roaming)

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Light SelfLight SelfLight SelfLight Self----Adaptive FeaturesAdaptive FeaturesAdaptive FeaturesAdaptive Features

• The brightness is set to 125.

• For bulk-data transfer, compress the data before uploading to

a server. The server must decompress the data after receiving

it.

• Check for high speed network before streaming video

contents or transferring bulk data.

• If highly accurate location is not needed then use coarse

location information for the mapping functionality.

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Conditions for Medium SelfConditions for Medium SelfConditions for Medium SelfConditions for Medium Self----AdaptionAdaptionAdaptionAdaption

• Triggered when one of the following is true

• Condition 1

– (10<B<50) and (S == discharging or S == USB charging) and

(C>31) and (L != roaming)

• Condition 2

– (1<B<10) and (S == anything) and (C<10) and (L ==

anything)

• Condition 3

– (51<B<75) and (S == anything) and (C == anything) and (L

== travelling abroad)

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Medium SelfMedium SelfMedium SelfMedium Self----Adaptive FeaturesAdaptive FeaturesAdaptive FeaturesAdaptive Features

• Tone down brightness to 75. This degrades the user experience to some

extent if the user prefers higher brightness level.

• Network operations are preferred to be done on high speed networks like

Wi-Fi/3G. If none of them are available and EDGE has to be used, notify

the user about the same and ask if the user would like to continue to use

EDGE.

• Transferring bulk data over EDGE should be avoided. This is a user feature

adaption in the application.

• Establishing multiple connections to stream HD videos or downloading

high volume data should be avoided.

• For scheduling background updates, inexact timer must be used. In this

case, Android system will couple several network operations together to

conserve battery and bandwidth.

• More features are given in the paper.

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Conditions for Strong SelfConditions for Strong SelfConditions for Strong SelfConditions for Strong Self----AdaptionAdaptionAdaptionAdaption

• Triggered when one of the following is true

• Condition 1

– (B<10) and (S == anything) and (C>31) and (L == anything)

• Condition 2

– (11<B<50) and (S == anything) and (C == anything) and (L

== travelling abroad)

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Strong SelfStrong SelfStrong SelfStrong Self----Adaptive FeaturesAdaptive FeaturesAdaptive FeaturesAdaptive Features

• Reduce brightness to 30 which minimizes the power consumption at display.

• Defer network operations from the application and notify the user about the same. This includes taking backup in remote server, streaming audio or video files and downloading bulk data. This is another user feature adaption done to make the dying battery last longer.

• By default the mapping feature is not offered in this profile as network operations are turned off. But there is an option where the user can override the settings and use only wireless network location to get the location.

• Stop background updates or any less important services.

• Stop computationally expensive parts of the applications.

• Do not show in-app advertisements.

• Avoid using sensors if possible. For example, do not change the view based on rotation of the screen.

• For video playback from the memory, reduce the size of viewing window. For audio playback, reduce the volume.

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ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Results

• Conclusion

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ResultsResultsResultsResults

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ContentsContentsContentsContents

• Introduction

• Lessons Learnt from Power Monitor

• Self-Adaptive Framework

• Prototype Implementations

• Result

• Conclusion

6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 26

ConclusionConclusionConclusionConclusion

• Presented a self-adaptive framework for

Android application development.

• Monitors several parameters, analyzes them

and triggers the appropriate self-adaptive

profile.

• Prototype application and validation through

promising results.

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6-Aug-14 Self-Adaptive Battery and Context Aware Mobile Application Development 28