measurements of energy consumptions in mobile …829733/fulltext01.pdf · consumption in mobile...

Master ThesisElectrical EngineeringMarch 2012

Measurements of EnergyConsumption in Mobile

Applications with respect toQuality of Experience

Sai Suren Kumar KasireddyVishnuvardhan Reddy Bojja

School of ComputingBlekinge Institute of Technology37179 KarlskronaSweden

This thesis is submitted to the School of Computing at Blekinge Instituteof Technology in partial fulfillment of the requirements for the degree ofMaster of Science in Electrical Engineering. The thesis is equivalent to 40weeks of full time studies.

Contact Information

Author(s):Sai Suren Kumar KasireddyVishnuvardhan Reddy BojjaE-mail: [email protected],[email protected]

University advisor(s):

Dr. Markus Fiedler, Prof.COM/BTH

School of ComputingBlekinge Institute of Technology371 79 KARLSKRONA SWEDEN

Internet: www.bth.se/comPhone: +46 455 385000SWEDEN

Acknowledgment

First of all, we are indebted to our supervisor, Prof. Markus Fiedler for hisvaluable guidance and providing us with all the necessary equipment alsofacilitating a suitable environment to carry out this work. We also expressour sincere gratitude to him for his moral support and the time that he hasspent for us throughout the course of our Thesis.

We would also like to thank Dr. Roman Weidlich for his support andhelp throughout the research.

We are greatly thankful to our beloved parents for their relentless sup-port that helped us to reach our goals.

Finally, we offer our sincere thanks to our friends and colleagues for theirvaluable contributions and making this work, a success.

Sai Suren Kumar KasireddyVishnuvardhan Reddy Bojja

3

Abstract

Nowadays, Third Generation (3G) mobile phones equipped with powerfulhardware are becoming popular and dominating the market of cellular com-munication systems. Features such as music and video players, in-builtGlobal Positioning System (GPS) receivers, navigation maps, Internet con-nectivity and high resolution cameras has converted mobile phones into socalled Smartphones. With the increase in applications and services, limita-tions on energy consumption are also increasing. Therefore, it is more im-portant for manufacturers to find effective means of increasing battery lifeof mobile phones, as the mobile device itself is energy consuming and longeroperational times are demanded by customers. Good energy mangement inmobile phones requires a good understanding of the energy usage in mobilephones. To this end, this thesis report presents the results of power and en-ergy consumption measurements conducted on available Smartphones. Theservices under investigation includes basic Smartphone functionalities andfew Internet services are studied and conclusions were drawn. This paperpresents a cost effective methodology for reliable measurements of energyon Smartphones. It also examines the effect of operating systems on en-ergy consumption in mobile phones and reports less energy consumption forAndroid supported phones. The energy consumption of these Smartphoneswith respect to various applications has been studied and related to Qualityof Experience of users’. Based on the results conclusions were drawn.

Keywords: Mobile services, Smartphones, Third generation (3G), PowerMonitor, Quality of Experience (QoE).

i

Contents

Acknowledgment 3

Abstract i

Contents ii

List of Abbreviations vi

List of Figures vii

List of Tables ix

Introduction 1

1 Problem Identification 21.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.3 Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.4 Research Questions . . . . . . . . . . . . . . . . . . . . . . . . 41.5 Research Methodology . . . . . . . . . . . . . . . . . . . . . . 51.6 Thesis Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Related Study 8

2 Literature Review 92.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.2 Network Technologies . . . . . . . . . . . . . . . . . . . . . . 9

2.2.1 Wi-Fi . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.2.2 3G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.3 Operating Systems in Mobile Phones . . . . . . . . . . . . . . 10

ii

2.4 Limitations of Mobile Devices . . . . . . . . . . . . . . . . . . 122.5 Energy Consumption Measurements . . . . . . . . . . . . . . 142.6 Research Gap . . . . . . . . . . . . . . . . . . . . . . . . . . . 142.7 Energy Meters . . . . . . . . . . . . . . . . . . . . . . . . . . 152.8 Smartphone Power Profiling and Battery Life Testing . . . . 152.9 Customer Perspectives . . . . . . . . . . . . . . . . . . . . . . 162.10 Mobile Data Services . . . . . . . . . . . . . . . . . . . . . . . 172.11 Quality of Experience . . . . . . . . . . . . . . . . . . . . . . 182.12 QoE Perception Factors . . . . . . . . . . . . . . . . . . . . . 18

Implementation 20

3 Implementation 213.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.2 Configuration and Settings . . . . . . . . . . . . . . . . . . . 213.3 Connecting and Testing Copper Tape Connections . . . . . . 233.4 Mobile Device Power Monitor . . . . . . . . . . . . . . . . . 233.5 Power Monitor GUI . . . . . . . . . . . . . . . . . . . . . . . 253.6 Evaluation of Power Monitor Log Files . . . . . . . . . . . . . 263.7 Trial Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . 273.8 Description of Test Cases . . . . . . . . . . . . . . . . . . . . 28

3.8.1 Test Case 1: Voice Call . . . . . . . . . . . . . . . . . 283.8.2 Test Case 2: SMS . . . . . . . . . . . . . . . . . . . . 283.8.3 Test Case 3: Camera . . . . . . . . . . . . . . . . . . . 293.8.4 Test Case 4: Recording and Playing a Video . . . . . 293.8.5 Test Case 5: Bluetooth . . . . . . . . . . . . . . . . . 293.8.6 Test Case 6: MP3 Song . . . . . . . . . . . . . . . . . 293.8.7 Test Case 7: YouTube Video . . . . . . . . . . . . . . 303.8.8 Test Case 8: Browsing Gmail . . . . . . . . . . . . . . 303.8.9 Test Case 9: Browsing Facebook . . . . . . . . . . . . 30

3.9 Legend Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . 313.10 Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Results 32

4 Results 334.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334.2 Energy Calculations . . . . . . . . . . . . . . . . . . . . . . . 334.3 Energy Measurements of Basic Applications . . . . . . . . . . 34

4.3.1 Voice Call . . . . . . . . . . . . . . . . . . . . . . . . . 344.3.2 SMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.3.3 MP3 Song . . . . . . . . . . . . . . . . . . . . . . . . . 37

iii

4.3.4 Bluetooth . . . . . . . . . . . . . . . . . . . . . . . . . 384.3.5 Recording and Playing . . . . . . . . . . . . . . . . . . 394.3.6 Camera . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.4 Internet Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . 414.4.1 Energy Consumption for HSDPA . . . . . . . . . . . 414.4.2 Energy Consumption for Wi-Fi . . . . . . . . . . . . 424.4.3 Energy Consumption in Sony Ericsson Xperia . . . . 42

4.5 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Survey Results 44

5 Survey Results 455.1 Device Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . 465.2 Application Usage . . . . . . . . . . . . . . . . . . . . . . . . 475.3 Battery Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485.4 Battery Backup . . . . . . . . . . . . . . . . . . . . . . . . . . 495.5 Network Usage . . . . . . . . . . . . . . . . . . . . . . . . . . 495.6 Willingness . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.7 Quality Parameters . . . . . . . . . . . . . . . . . . . . . . . . 515.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

6 Conclusions 536.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2 Research Questions and Answers . . . . . . . . . . . . . . . . 546.3 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Appendix 56

A Experiments and Analysis data 57A.1 Hardware and Software Requirements for the Workstation . . 57A.2 Data Exporting Features of Power Monitor . . . . . . . . . . 57A.3 Average Power Consumptions Values of 10 Trials for Basic

Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . 58A.3.1 Sony Ericsson C902 . . . . . . . . . . . . . . . . . . . 58A.3.2 Sony Ericsson Xperia . . . . . . . . . . . . . . . . . . 59A.3.3 Sony Ericsson Elm . . . . . . . . . . . . . . . . . . . . 59A.3.4 HTC Dream . . . . . . . . . . . . . . . . . . . . . . . 60

A.4 SMS Growth . . . . . . . . . . . . . . . . . . . . . . . . . . . 60A.4.1 Analysis of SMS for Sony Ericsson C902 . . . . . . . 61A.4.2 Analysis of SMS for Sony Ericsson Xperia . . . . . . 62A.4.3 Analysis of SMS for Sony Ericsson Elm . . . . . . . . 63A.4.4 Analysis of SMS for HTC Dream . . . . . . . . . . . 64

iv

A.5 Specifications and Features of Smartphones . . . . . . . . . . 65A.5.1 Specifications of Sony Ericsson C902 . . . . . . . . . . 65A.5.2 Specifications of Sony Ericsson Elm . . . . . . . . . . 65A.5.3 Specifications of Sony Ericsson Xperia X8 . . . . . . . 66A.5.4 Specifications of HTC Dream . . . . . . . . . . . . . . 66

A.6 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Bibliography 68

v

List of Abbreviations

Acronyms DescriptionAC Alternating CurrentCDMA Code Division Multiple AccessDC Direct CurrentDSS Direct Sequence Spread SpectrumFDM Frequency Division MultiplexingGPS Global Positioning SystemGSM Global System for Mobile CommunicationsGUI Graphical User InterfaceHSDPA High Speed Data Packet AccessHS-PDSCH High Speed Packet Downlink Shared ChannelMMS Multimedia Messaging ServiceOS Operating SystemQoE Quality of ExperienceQoS Quality of ServiceSMS Short Messaging ServiceTD-SCDMA Time Division Synchronous Code Division Multiple AccessUMTS Universal Mobile Telecommunications SystemVoIP Voice over Internet ProtocolWCDMA Wideband Code Division Multiple AccessWi-Fi Wireless FidelityWiMAX Worldwide Interoperability for Microwave AccessWLAN Wireless Local Area NetworksWWW World Wide Web2G Second Generation3G Third Generation3GPP Third Generation Partnership Project

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List of Figures

1.1 Increasing services and features on Smartphones leads to in-crease in energy consumption . . . . . . . . . . . . . . . . . . 3

2.1 Smartphone OS market share . . . . . . . . . . . . . . . . . . 122.2 Smartphone Power Profiling and Battery Life Testing . . . . 16

3.1 Application of copper tape over insulating tape to Mobilephone battery . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2 Mobile Device Power Monitor Hardware . . . . . . . . . . . . 243.3 GUI for Power Monitor Tool . . . . . . . . . . . . . . . . . . 253.4 GUI for Power Monitor Tool after connecting to a device . . 263.5 Experimentation Process Flowchart . . . . . . . . . . . . . . . 273.6 Legend Dialog Box . . . . . . . . . . . . . . . . . . . . . . . . 31

4.1 Power Consumption of the Smartphones for a Voice Call . . . 354.2 Power Consumption of the Smartphones for a SMS of 160

characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.3 Power Consumption of the Smartphones for a SMS of 320

characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374.4 Power Consumption of the Smartphones for a MP3 Song . . . 384.5 Power Consumption of the Smartphones for Bluetooth . . . . 394.6 Power Consumption of the Smartphones for Recording and

Playback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404.7 Power Consumption of the Smartphones for Camera application 41

5.1 Device usage . . . . . . . . . . . . . . . . . . . . . . . . . . . 465.2 Application usage in Smartphones . . . . . . . . . . . . . . . 475.3 Frequency of charging the user mobile phone . . . . . . . . . 485.4 Battery Backup of users’ Smartphones . . . . . . . . . . . . 495.5 Network preference based on connectivity . . . . . . . . . . . 495.6 Network preference based on browsing habits . . . . . . . . . 505.7 Willingness to use another network . . . . . . . . . . . . . . . 51

A.1 Growth of Text Messaging . . . . . . . . . . . . . . . . . . . . 60

vii

A.2 Various parameters for playing a game for 300 s in Sony Er-icsson C902 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

viii

List of Tables

3.1 Work Station Configuration . . . . . . . . . . . . . . . . . . . 21

4.1 Energy Consumption Measurements: Voice Call . . . . . . . . 344.2 Energy Consumption Measurements: SMS . . . . . . . . . . . 364.3 Energy Consumption Measurements: MP3 song . . . . . . . . 374.4 Energy Consumption Measurements: Bluetooth . . . . . . . . 384.5 Energy Consumption Measurements: Recording & Playing . . 394.6 Energy Consumption Measurements: Camera . . . . . . . . . 404.7 Energy Consumption Measurements: HSDPA . . . . . . . . . 414.8 Energy Consumption Measurements: Wi-Fi . . . . . . . . . . 424.9 Energy Consumption Measurements: Wi-Fi & HSDPA . . . . 42

5.1 Comparison of Network Usage and User Preference . . . . . 505.2 Quality Parameters . . . . . . . . . . . . . . . . . . . . . . . . 51

A.1 File Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . 58A.2 Sony Ericsson C902: Basic Applications . . . . . . . . . . . . 58A.3 Sony Ericsson Xperia: Basic Applications . . . . . . . . . . . 59A.4 Sony Ericsson Green: Basic Applications . . . . . . . . . . . . 59A.5 HTC Dream: Basic Applications . . . . . . . . . . . . . . . . 60A.6 Energy Consumption Measurements: SMS . . . . . . . . . . . 61A.7 Energy Consumption Measurements: SMS . . . . . . . . . . . 62A.8 Energy Consumption Measurements: SMS . . . . . . . . . . . 63A.9 Energy Consumption Measurements: SMS . . . . . . . . . . . 64A.10 Specifications of Smartphones: Sony Ericsson C902 . . . . . . 65A.11 Specifications of Smartphones: Sony Ericsson Elm . . . . . . 65A.12 Specifications of Smartphones: Sony Ericsson Xperia X8 . . . 66A.13 Specifications of Smartphones: HTC Dream . . . . . . . . . . 66

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Introduction

1

Chapter 1

Problem Identification

1.1 Introduction

The rapid advancement in wireless technologies along with a major shiftfrom purely voice only services to a combined package of voice and videodata services have left the operators to be on their toes all the time. TheSmartphones are ushering in the real age of ubiquitous computing, providingmany valuable services which cannot be undervalued. The important fea-tures provided by them include voice, video, Multimedia Messaging Service(MMS) along with normal text mode communication using latest wirelesstechnologies such as, Wireless Fidelity (Wi-Fi), 3G and Wireless Local AreaNetwork (WLAN) etc. Along with the availability of these promising ser-vices and applications, mobile phones are also becoming more and moreenergy-hungry, thereby reducing operational time for the user [1].

Different vendors distinguish among the mobile devices by the servicesthey offer and use the fully available computational power to develop newservices. As shown in the Figure 1.1 the more services and features a Smart-phone offers, larger the energy consumption can be. A phone, if runs out ofbattery, cannnot provide access to a mobile service for its users, thus reduc-ing the revenue generated by the service to the service provider. This leadsthe manufacturers to pay interest in developing solutions to extend batterylife time and operational time.

2

CHAPTER 1. PROBLEM IDENTIFICATION 3

Figure 1.1: Increasing services and features on Smartphones leads to increasein energy consumption [2]

With the rise in mobile networking there is a corresponding rise in thenumber of mobile devices and power to them. However, advancements inbattery technologies haven’t been showing the same type of success. Asfar as mobile devices are concerned, constraints such as limited size, lowheat dissipation, increasing mobile device capabilities have been showingmore pressure on the manufacturers to develop better batteries [3]. Thisis more evident in the most commonly used mobile devices such as laptopsand Smartphones [4].

Smartphones are not anymore mere low-computational mobile devices.Instead they offer extreme capabilities of processing and networking withthe ability to access almost any type of network. However, they are on aconstant look for power to go on and continue to stay on. From here comesthe need to study the energy consumption levels in Smartphones with respectto various applications.

1.2 Motivation

The need for Wi-Fi based phones is increasing rapidly due to the ubiquitouspresence of WLANs. Power consumption is the vital issue in selection ofa mobile phone [5]. Since all these devices make use of rechargeable bat-teries, the appealing services and features unfortunately drain lot of energystored in a capacity limited battery of a mobile phone. Achieving low powerconsumption for wireless devices has become a key design issue [6] whichmotivated us to carry out this research. For any mobile device the two ma-


jor constraints are battery life time, size and weight [7]. These devices needmore processing power but their energy consumption should be less to savebattery power.

In [8, 9, 10] one can find the problems being faced by the mobile phoneusers with the inaccuracy in battery meter indications. From this it isevident that Battery meter indications in mobile phones are not 100 % trueand users cannot rely on the predicted values to estimate the amount ofcharging left for further usage of mobile phone. In [11, 13] it was stated thatbattery meter applications devoloped for mobile phones were not satisfactoryand users are highly disappointed with these applications. Mismatch in thereadings of battery meter provided by manufacturer in mobile phone andinstalled battery meter applications [12] makes it necessary for users to knowthe accurate readings of battery’s energy drain which in turn requires theknowledge of energy consumption of different applications in a mobile.

In [1, 13] there are various reviews and tips on ways to increase batterylife of a mobile phone. In [14] suggestions for maximising the battery lifeof an Android mobile were provided. It is a common problem among phonemanufacturers in finding a way to extend battery life of their devices andallow users to use mobile services for a longer time [1], is also the motivationbehind carrying out this research.

In order to provide guidelines for design, provisioning and operations ofmobile services, applications such as voice, video or any other multimediaapplications need to be identified and quantified to obtain a compromisebetween Quality of Experience (QoE) and energy consumption, which hasbeen the main motivation towards this research.

1.3 Objective

The main objective of this research is to establish an experimental hardwaresetup to provide reliable measurements of energy consumption in hand-helddevices. The most commonly used network technologies to connect to theInternet using Smartphones are namely High Speed Data Packet Access (HS-DPA), Wi-Fi and Third Generation (3G). More importantly, it also bringsawareness to the users of the mobile devices that would help them in choosinga network connection. To conclude, this research introduces useful informa-tion on energy consumption measurements and impacts of the measuremntson QoE.

1.4 Research Questions

This research aims at providing answers to the following research questions


1. Is there a methodology to measure the energy consumption of a mobilephone battery in a real time environment?

2. Does the energy consumption depend on the operating system used inthe mobile phone?

3. How can we relate QoE and energy consumption in a mobile device?

1.5 Research Methodology

The following steps explain the research methods those were adopted in thisresearch at various stages to answer the research questions, thus fulfillingthe aims and objectives of this research.

1. In the initial phase of the research, a literature survey related to mo-bile operating systems, energy consumption, QoE constraints and inparticular regarding parameters affecting them will be carried out.

2. A study about the various energy meters will be carried out and anappropriate one that suits the research were identified.

By following the steps 1 & 2, solution to the first research questionabout the energy meter and methodology to measure energy consump-tion of a mobile phone battery in real time will be achieved.

3. In the second phase an analysis of different 3G mobiles and the basicservices and applications in which users are mostly interested was done.

4. As a part of this, the concepts of QoE, energy consumption and bat-tery life time in mobile phones and parameters that affect them werestudied.

5. After the literature review, ascertaining the appropriate energy meterand list of mobiles & applications follows actual experimental stage.

6. In the next stage, experimentation with different mobiles (most com-monly used Smartphones depending on availability) and applications(includes real time and non real time traffic) under different wirelessnetworks (Wi-Fi, 3G) and measure the amount of energy being con-sumed for the selected applications.

By following the above methodology and performing the experimen-tation, dependency of energy consumption on OS can be determined.By this the second research question can be answered.


7. A user related survey which can assist in QoE analysis was carriedout.

8. The results obtained from experiments are to be quantitatively ana-lyzed and conclusions are drawn based on energy consumption.

9. Finally, a set of conclusions and few recommendations based on theresults of our analysis were provided.

With the help of the literature review, user related survey, resultsobtained from experimentation, QoE and energy consumption can berelated in order to provide answer to the last research question.

1.6 Thesis Layout

The rest of the document is organized as follows: Chapter two gives anoverview of the various network interfaces and type of operating systemsexisting in the market. This chapter discusses about the related work donein this area and research gap that has been identified for carrrying out thistype of research. It also gives a breif account of power measurements inSmartphones and various energy meters available for this purpose. It alsocontains various QoE factors that are considered while choosing a particularSmartphone and network interface. Information about various mobile ser-vices is also included.

Chapter three provides an understanding of the experimental setup andthe tools that were used in this research. Brief details about the connectionsand configurations of the setup is included in this chapter. It discusses aboutthe various tasks that were chosen to perform this study. The conditionsand network environment under which the experimentation was carried outis also explained. Finally this chapter is concluded with the parametersmeasured and the tools that are used to export data from Power Monitor.

Chapter four discusses about the analysis of the measurements and theresults. The results are presented in tables and graphs. Few observatiionsfrom the results were included. This chapter is concluded with the explan-tion regarding the validation of results.

Chapter five gives an overview of the results obtained from survey filledby 100 participants from various parts around the world. Statistics of thesurvey were presented in the form of tables and graphs.

The last chapter finally concludes the research work by providing answersto the research questions in detail. It also discusses the future scope of this


research in relevance to the further study.

Related Study

8

Chapter 2

Literature Review

2.1 Introduction

In this chapter, the most familiar wireless networks that are being used withmobile phones are listed. Different types of operating systems used in theSmartphones are presented in brief. The importance of battery life in mobilephones and limitations of battery in mobile devices are discussed in detail.This is followed by related work carried in measuring the energy consumptionin mobiles and various DC energy meters available for accomplishing it.Finally, the chapter is concluded with a brief discussion on several factorsthat affect QoE in mobile services.

2.2 Network Technologies

The increasing demand for high speed internet access is due to the explosivegrowth of Internet over the last decade [15]. Broadband wireless technologiesare increasingly gaining popularity by the successful global deployment ofthe Wireless Personal Area Networks (WPANs) (Bluetooth- IEEE 802.15.1),Wireless Local Area Networks (Wi-Fi- IEEE 802.11n), and Worldwide In-teroperabiity for Microwave Access (WiMAX- IEEE 802.16) [15].

2.2.1 Wi-Fi

Wi-Fi stands for Wireless Fidelity, generally referring to any type of 802.11networks. 802.11b, 802.11g, 802.11a. Wi-Fi refers to three types of wirelessprotocolsIEEE 802.11b (”Wireless B”)IEEE 802.11a (”Wireless A”)IEEE 802.11g (”Wireless G”)

9

CHAPTER 2. LITERATURE REVIEW 10

802.11b It is stable and cost effective standard which runs in the 2.4 GHzrange. It has 11 channels, 3 non-overlapping and is supporting rates from 1to 11 Mbps, and uses Direct Sequence Spread Spectrum (DSSS) technology.

802.11g It is an extension of 802.11b but has a shorter range than 802.11band also back ward compatible with 802.11b. It runs at 54 Mbps and usesFrequency Division Multiplexing (FDM) technology.

802.11a It is completely different from the other two but has shorter rangewhen compared to both 802.11a and 802.11g. It has 12 channels, 8 non-overlapping, supporting rates from 6 to 54 Mbps and uses FDM technology.

2.2.2 3G

The capability to provide various multimedia services is the most promi-nent characteristic of 3G which can support a wide variety of data rates asmentioned below [16]:

• 144 kbps in high mobility environment

• 384 kbps in medium or low mobility environment

• 2 Mbps in static state

Wideband Code Division Multiple Access (WCDMA), Code Division Mul-tiple Access (CDMA2000) and Time Division Synchronous Code DivisionMultiple Access (TD-SCDMA) are the three mainstream 3G standards.There are also other implementations in 3G like Universal Mobile Telecom-munications System (UMTS) and HSDPA supporting data rates as high as14.4 Mbps.

HSDPA is not only an advanced technology for high data rate mobilecommunication but also a remarkable one for 3G service. It is the fifthrelease of WCDMA standardized by Third Generation Partnership Project(3GPP) developed for mobile data service. It produces high data rates ondownlink using High Speed Packet Downlink Shared Channel (HS-PDSCH)for high data rate service [17].

2.3 Operating Systems in Mobile Phones

Smartphones are attracting customers with a wide-variety of applicationsleading to higher battery consumption. Since battery life has become amajor challenge in Smartphones, researchers are now focusing on the im-provement of battery life of these devices. According to UK-based research


firm [18] global Smartphone sales will increase from around 165.2 million in2009 to 422.96 million in 2013.

The type of OS used in the mobile determines the type of applicationsand functionality of the phone. The software platforms that fragment themobile market are Palm OS, Blackberry, Windows Mobile, Android, andiPhone OS. Frequently updated platforms include Palm and iPhone OSfollowed by Blackberry and Windows Mobile whereas Symbian is not sofrequently updated and also installing latest update is a bit clunky. AsSmartphone offers different operating conditions and features depending onthe type of OS used in them, both customers and researchers are focusingon this area.

• Android

• BlackBerry OS

• Windows Mobile

• iPhone OS

• Symbian

• Maemo

• Bada

Android A Linux based open source platform from Google. It has notbeen around for a long time so it does not appear on many current Smart-phones, but being developed by leading manufacturers [18].

BlackBerry OS Powering all the BlackBerry mobile phones, it is the bestoperating system for Email applications.

Windows Mobile Microsoft’s operating system specially designed forbusiness users with a host of speciality applications.

iPhone OS It was specially developed for Apple iPhone which is intendedfor individual customers so lacking some business functionalities.

Symbian Developed by Symbian Ltd., acquired by Nokia in 2008 and isin use by all Nokia Mobiles.

Maemo Nokia’s largest Linux based operating system which powers theNokia N900.


Bada It is developed by Samsung.

Figure 2.1: Smartphone OS market share [16]

Figure 2.1 depicts the share of different mobile operating systems in themarket. The description of these OS, their benefits and the competitionamong these OS were briefly discussed in [19].

2.4 Limitations of Mobile Devices

Though mobile devices are making it easier for users to communicate, manyusers get frustrated while accessing certain applications and services usingtheir mobile devices. This is largely due to the fact that mobile devices likeSmartphones are new and the technology is still emerging [20]. Some of themajor limitations are

1. Limited memory

2. Limited processing power

3. Battery consumption


4. Simplicity

5. Accessibility

Limited Memory The main challenge faced by software production andusage for mobile consumer devices is limitations in the memory. As thephysical memory is limited and the mobile devices do not support any virtualmemory, programs are forcibly terminated leading to fatal errors particularlyin situations where the operating system is running on low memory. Thislimits the length of emails, opening of attachments and the use of multipletabs in case of mobile phones. Currently the main aim of research worksbeing carried out on mobile devices is to improve memory management forperformance, safety, ease of use and efficiency [21].

Limited Processing Power Nowadays, mobile devices are becomingmore and more advanced in processing power when compared to earlierphones. Many Internet-based mobile services like online gaming, browsing,video streaming, VoIP, etc. require large amount of memory storage andhigh processing speed. Applying parallel processing to independent tasksefficiently reduces the power consumption [22].

Battery Consumption Battery plays a vital role in determining the mo-bility and portability of handheld devices. But they run out quickly, whichis said to be the major drawback in most handheld devices. Battery energyis very limited for mobile phones. The mobile phone’s hardware and soft-ware are designed in such a way that they reduce the energy consumption asmuch as possible, increasing the battery life. Battery life is a crucial factorin case of portable wireless devices, especially in cellular systems. Hencethere is a need for saving energy consumption at terminal side [23].

Simplicity Mobile manufacturers are aiming at reducing the size of mobilephones to make them more portable, which also reduces the size of keypadand screen. The usage of the mobile phone is limited by size of key padand less number of cursor keys which makes them difficult to users whilenavigating through remote sites with large content. User interfaces need tobe simple and user friendly as it becomes highly impractical to read manualswhile performing certain operations. Graphical capability is a constraintwhile developing attractive interfaces [20].

Accessibility Current generation mobile services have more than one net-work interface, so the accessibility varies depending on the interface used bythe user in order to connect to a network. Coverage area is the constraint


that has to be taken into consideration while comparing two wireless tech-nologies [20]. Accessibility is one of the major issue that affects user’s choiceof a particular mobile network.

2.5 Energy Consumption Measurements

Measurements conducted on a Nokia N95 mobile to show the energy con-sumption for the most widely used services, namely SMS, voice and datausing both Global System for Mobile communications (GSM) and UniversalMobile Telecommunications System (UMTS) are presented in [1]. In [24]limitations of black box based energy measurement techniques have beenaddressed and also an accurate method for measuring energy consumptionwithout additional hardware has been proposed. An investigation of con-sumer attitude towards energy consumption of mobile phones and mobileservices with a questionnaire study is done in [25] depicts that customersare eager to know about the energy consumption of mobile applications andservices. In [26] a new buffer management policy for reducing power con-sumption for mixed mobile disk and flash memory is proposed.

In [27] authors have depicted with the help of simulation results howthe amount of energy saving in mobile handheld devices is affected withvariations in transmission duration. They have also presented a strategywhich can conserve energy of the mobile nodes and thus increasing the life-time of the network. A quantitative study of YouTube’s energy consump-tion in mobile devices based on the measurements carried out on NokiaS60 mobile phones and further investigation of the energy characteristicsbased on network access technology Wideband Code Division Multiple Ac-cess (WCDMA) and WLAN, download technology and storage media usedwas carried out in [28]. Energy consumption at mobile terminals can beneglected in terms of carbon dioxide emission, but limitations of its batteryperformance leads to energy starvation in mobile devices [23].

2.6 Research Gap

The research work carried out in [6, 7, 24, 25, 26, 27, 28, 29, 30] has nosignificant contribution towards mobile phones supporting 3G & 4G tech-nologies and the promising services like broadband data services with videoand multimedia, superior voice quality. Even though in [1] efforts have beenmade towards increasing the battery life of a mobile, a methodology whichcan reliably measure energy has not been addressed.

Researchers have contributed a lot in energy measurements of mobile ser-vices but very few researches have contributed towards hardware based en-


ergy measurements. So it is necessary to have hardware based energy con-sumption measurements in Smartphones so as to benifit both the customersand mobile manufacturers. Very little effort have been made in relatingthese measurements to QoS which is the most important characteristic forthe benefit of users as well as manufacturers.

2.7 Energy Meters

Generally, most of the energy meters available in the market are used tomeasure the Alternating Current (AC) power in house hold appliances. SoDirect Current (DC) energy meters that measure the power in the range ofa mobile battery are very rarely available in the market. In [1] AGILENT66319D is used as a multimeter to measure the current and voltage but notenergy directly. This research [1] was supported by DOCOMO Communi-cations Laboratories Europe and was partially funded by the X3MP projectgranted by Danish Ministry of Science, Technology and Innovation. Since itis very costly, there is a definite need to identify a meter which gives directreadings of energy consumed to reduce circuit and computational complex-ity. The energy meter used for this research [31, 32] provides atleast thepower consumption values in log files from which the energy cosumptioncan be directly calculated with little computational complexity. The advan-tages of the meter are as follows:Firstly it is cost effective when compared to the other meter and is reliableas the sampling rate is very high namely 5000 samples of voltage and cur-rent per second. So the measurements are assumed to be highly precise andaccurate if experimented with proper care which will be discussed later indetail.

2.8 Smartphone Power Profiling and Battery LifeTesting

The most challenging aspects of designing and launching a Smartphone isbattery life. So a complete and objective yet efficient methodology to testbattery life, power and energy consumption is an essential part of everydevice’s launch process. For Smartphones, the approaches to test powerconsumption and to consequently measure the expected battery life are dis-cussed in detail below [33]:

Component Level The device power consumption is the aggregate ofmeasured power consumption at component level. Though this method isproven to be more accurate and results are reproducable, more efforts andmore cost is required to perform it. The requirement of detailed hardware


and software doccumentations makes this approach difficult in real time [33].

Device Level Power is measured at the aggregate point of battery con-nection for variety of scenarios of the device usage. This method is morepractical and has proven to be more useful for users as well as operators thanenergy measuremnts at component level. Validity of the results depends onhow accurately the device under test is prepared for the test. As theresultsvary from run to run it is necessary to repeat the tests to achieve stablityand statistical significance [33].

This research was carried out considering the application level energymeasurement similar to kind of device level power measurement. In thisresearch energy consumption of application is measured as a whole for tworeasons. Firstly users are not much bothered about individual componentenergy consumption as they cannot change the hardware of the Smartphonesand Secondly, as the overall energy consumption includes energy consump-tion of all the components user will be provided with the knowledge regard-ing energy consumption of certain application. As this research is initiatedwith an objective to benefit operators and users for whom individual com-ponent power or energy consumption is of less importance were not takeninto consideration.

Figure 2.2: Smartphone Power Profiling and Battery Life Testing [33]

2.9 Customer Perspectives

According to ICT statistics 2010, there is rapid growth in usage of Internet.It was estimated that the number of users may surpass 2 billion of which 1.2


billion will be in developing countries [34]. As per the statistics, China isthe largest Internet market with more than 420 million Internet users. 90%of world population have access to mobile networks. There is a rapid changeof technology from 2G to 3G, by the end of 2010 it is estimated that mobilesubscribers may reach 5.3 billion which includes 940 million subscriptions to3G services [34]. Mobile cellular growth is slowing worldwide, at the sametime the share of mobile subscriptions in developing countries is estimated toincrease from 53% in 2005 to 73% in 2010. The emergence of 3G networksallows users to access through mobile networks particularly in developingcountries where fixed broadband infrastructure is limited [34].

Despite of many services that are available through the Internet, choosingthe type of network to access the service depends on suitability of thatservice to the network regardless of the network interface that is being used.Suitability of a network depends on user needs and properties.

2.10 Mobile Data Services

Mobile data services are proliferating along side traditional voice servicesand are becoming the pivotal business strategies for mobile operators. Thefollowing list covers some of the revenue generating data services which areexisting and few are going to come in near future [35]:

• Short messages (SMS)

• Multi Media Messages (MMS)

• Community chats, forums

• Web browsing

• Email access, Email to SMS access

• Ring tones and graphics download

• SMS votes, alerts

• Interactive gaming

• Video and game download

• Streaming

• Video Sharing (VS)

• Mobile office (Email, browsing, etc.)

• M-payments, M-banking, M-booking, M-brokering, M-ticketing


• Proximity services

• Push to talk over Cellular (PoC)

• Presence

• Conferencing

• Instant messaging

SMS It has become the prominent and important service of communica-tion through mobile phone. Statistics [34] say that number of SMS sentglobally has been tripled from 2007 to 2010. Every second 200000 SMS aresent and large amount of revenue in mobile services is being generated fromthis. Keeping its importance in view, emphasis has been given in this re-search in analyzing the SMS sent using Smartphones.

The requirements of these applications vary from one another and man-aging the performance of these applications, has become a challenge formobile operators. Without over-dimensioning the network resources and toprovide the best-of-class services to the end-user, managing the performanceof these applications has become essential [34].

2.11 Quality of Experience

The way users perceive the performance of network or a mobile service isthe ultimate way of measuring that particular service or network [36]. Thisperception is termed as QoE which determines the usability of the serviceor application in subscriber’s perspective.

2.12 QoE Perception Factors

The following are some of the critical perception factors of QoE [37]:

1. Speed

2. Accessibility

3. Session quality

4. Integrity

5. Flexibility


Speed It plays a prominent role in QoE of a user because it decides howfast a user can connect to a network. Users are mostly concerned about thespeed of the network. In case of the voice services users may expect fastconnections whereas while accessing information through internet such aswatching a video online, downloading an attachment, playing games online,etc., some amount of delay is tolerable.

Accessibility It reflects the success rate at which the user is guaranteedaccess to a service. It depends on several factors. For instance, in case ofvoice service the success rate can be expressed related to network coverage,signal strength .

Session Quality It is used to express the quality of session in which thecustomer is using a service. Many network parameters like packet loss rate,end to end delay, jitter will have influence on the session quality. This factorwill actually benefit the network operator to improve the performance of thenetwork and maintain good Quality of Service (QoS).

Integrity It is concerned about the integrity of service used by the cus-tomer. Integrity of a service is affected by various factors depending on thetype of service. For instance, in case of video streaming, integrity can beaffected by network delay and jitter where as in case of voice service, it canbe affected by unclear voice quality.

Flexibility It indicates whether the user is able to use the service simplyand easily.

Gaining an understanding of the factors which contribute to users per-ception and applying the knowledge to define the operating requirementshelps in delivering high QoE [36].

Implementation

20

Chapter 3

Implementation

3.1 Introduction

This chapter deals with the hardware instrument, Mobile Device PowerMonitor, its configuration and settings. It also tells us about the GUI of thesoftware tool provided along with the device and the detailed explanationof test cases that are considered for this research. The trial flow chart andparameters which the Power Monitor generates in the log file are presentedin detail. Finally, this section is concluded with the explanation regardingthe evaluation of log files generated by Power Monitor.

3.2 Configuration and Settings

Table 3.1: Work Station ConfigurationComponent Specifications

Processor Intel (R) core (TM)2 QuadCPU Q6600 @ 2.4 GHZ, 2.4GHZ

Internal Memory 2.75 GB RAM

Operating System Windows XP ProfessionalVersion 2002 Service Pack 3

Harddisk 250 GB

Table 3.1 lists the configurations of dedicated work station that is usedfor installing the Power Monitor GUI and carrying out this research. Sincethe sampling rate of Power Monitor is fixed by the manufacturer to 5000samples per second it requires moreprocessing speed if a test case has tobe run for longer duration. To eliminate all sort of technical disturbancesa specially integrated personal computer has been used in this research, so

21

CHAPTER 3. IMPLEMENTATION 22

that the Power Monitor doesn’t hang often.

Four Smartphones were used for this research are:

1. Sony Ericsson C902

2. Sony Ericsson Xperia

3. Sony Ericsson Greenheart or Sony Ericsson Elm

4. HTC Dream

Among the four mobiles, Sony Ericsson C902 and Sony Ericsson Elm areJava powered mobiles and the remaining two are Android mobiles. Settingsof mobiles were adjusted according to the requirements of test cases.

The test cases were planned by keeping in view of users interest in ex-isting applications of Smartphones and the time periods of these test caseswere planned accordingly. Keeping in mind regarding the availability, timeand cost constraints only four Smartphones were used for this research. At-tempts were made at the best to use more advanced Smartphones availablein the market.Telenor SIM cards were used for the research on both sides soas keep things in the same network.

Experiments were also carried on 2G phones, but it is not the area ofinterest in this research, the results were not presented in the main part ofthe work. Measuring the signal strength and data rates of HSDPA , Wi-Fiin mobile phones is a difficult task which was eliminated in this work. Sincethe experiments were conducted in single location, we expect that the signalstrength will not effect the measurements from trial to trial.


3.3 Connecting and Testing Copper Tape Connec-tions

Figure 3.1: Application of copper tape over insulating tape to Mobile phonebattery [32]

Insulating tape has to be applied over the voltage terminal of the batteryand copper tape is applied over positive and negative terminals as shownin Figure 3.1. Before connecting it to the Power Monitor, one has to checkfor the righteousness of the connections by placing the battery back intothe mobile phone, which should not power up. After ensuring proper con-nections and having the mobile ready for testing, one needs to connect themobile device to the Power Monitor as shown in Figure 3.2 and press theVout Enable button provided in GUI of Power Monitor. The mobile shouldpower up now and it is ready for testing.

3.4 Mobile Device Power Monitor

The Power Tool software and the Mobile Device Power Monitor hardwareprovide a robust power measurement solution for mobile powered devices.The Power Tool software and the Mobile Device Power Monitor hardwarecan analyze the power on any device that uses a single lithium (Li) battery.Electrical engineers and software developers can utilize the Power Tool soft-ware and the Mobile Device Power Monitor hardware to optimize the designand analyze the performance of their mobile devices [32].


Figure 3.2: Mobile Device Power Monitor Hardware [32]

Figure 3.2 shows the Power Monitor device which is used for experi-mentation in this research. The information regarding the installation ofPower Monitor GUI, connecting the mobile device for measurements andthe precautions to be taken during measurements can be found in [32].


3.5 Power Monitor GUI

Figure 3.3: GUI for Power Monitor Tool [32]

Figure 3.3 shows the Graphical User Interface (GUI) that is used by theuser to carry out the experimentation.


Figure 3.4: GUI for Power Monitor Tool after connecting to a device [32]

Figure 3.4 shows the Graphical User Interface (GUI) of the Power Moni-tor tool after connecting to a device. The main channel of the Power Monitorhas to be selected while carrying out the experimentation. Before startingthe experiment, select the Vout Enable so as to power the Smartphone fortesting. We can dynamically set the time period for stopping the tool eithermanually or automatically by adjusting the ’Set capture triggers’ settings.There are also provisions for copying the graph and statistics separately ifrequired. The data can be exported by selecting ’Export’ option provided inthe GUI and can be saved to the hard disk in different file formats mentionedin the appendix.

3.6 Evaluation of Power Monitor Log Files

Table A.1 indicates the file formats that the Power Monitor supports. Sincethey are of huge size they cannot be analyzed manually, so after extractingthe data from the power monitor, a script is developed in Perl language forevaluating the generated log files. Power consumption profiles are plottedusing MATLAB. Survey statistics are plotted using Microsoft Excel. The logfile consists of four columns,the first one indicates the time, the second oneindicates the instantaneous current value in mA,the third column containsinstantaneous power in mW and the last column indicates instantaneousvoltage value in V. Instantaneous power is the product of instantaneous


current and voltage. So only the instantaneous power values are used forthe measurements of energy which is calculated using the formula describedin section 4.2. The average value of energy for a trial is calculated by takingthe product of average power and time duration of the test run (which variesdepending on the test case). The averge power value is the average valueof huge number of samples of instantaneous power column in the log file.Both the calculations are made using PERL code. The average value andstandard devaition values are calculated in Excel.

3.7 Trial Flowchart

Figure 3.5 is the trial Flowchart which describes about how a mobile ap-plication is being tested for measuring the energy consumption. The timeperiod of the test case varies from application to application.

Figure 3.5: Experimentation Process Flowchart

For each test case described in the section 3.7, 10 trials were performedfor the basic applications. Due to cost and time constraints Wi-Fi andHSDPA tasks were tested 3 to 4 trials. Since the Smartphone is poweredfrom Power Monitor device, the voltage supplied is 3.70 V, the maximumvoltage of a battery.


3.8 Description of Test Cases

3.8.1 Test Case 1: Voice Call

The first and foremost use of a mobile phone is for making a voice call. Afterensuring all the connections are properly made, a voice call is initiated tothe other party mobile number. After the call is established and as sooon asother party lifts the call, run the Power Monitor for a period of 60 seconds.This time period has to be set automatically by setting the capture triggersin GUI to the required value which is 60 seconds in this case. So after60 seconds the power monitor automatically stops the measurement. Afterthe log file is exported measure the enrgy consumption of the testcase byspecifying start time is ’0’ and end time is ’60’ to the perl script which isbeing excuted in SSH client. Repeat the procedure for the ten trials andcalcualte the average value of energy and standarad deviation for the tentrials.

3.8.2 Test Case 2: SMS

SMS stands for Short Message Service. It consists of maximum upto 160characters. Here an effort has been made to analyze the effect of numberof characters of a SMS on energy consumption. So experimentation wascarried out on SMS of 160 and 320 characters.

1. SMS 160 Char: Make sure that the text you want to send is readyand after adding the recipient number run the Power Monitor. Pressthe send key, once the SMS is sent stop the Power Monitor. Thesample text that we have chosen for our measurements is ”Researchyour idea. Check the demand. A lot of people have great ideas, butthey don’t know if there’s a need for it.You also have to research yourcompetition.” which consists of 160 characters.

2. SMS 320 Char: Repeat the same procedure that you have done forSMS of 160 characters. The sample text we have chosen for this sce-nario is ” Though I had success in my research both when I was madand when I was not, eventually I felt that my work would be betterrespected if I thought and acted like a normal person.I don’t believe inwriting anything that I don’t know about or haven’t researched aboutpersonally. I like to transport the reader to places.” which consists of320 characters.

Once the power monitor is stopped manually, export the log file on tothe computer. Manually identify the time period over which the SMSis sent from the mobile. The start and end times can be obtained


correspondingly by sudden rise and fall in power values is the log file.Repeat the measurements to yield ten trials.

3.8.3 Test Case 3: Camera

This is the basic accessory in Smartphones. Turn on the camera applicationand run the Power Monitor. Access the camera for a period of 30 secondsfor taking snapshots and stop the Power Monitor automatically by adjustingthe capture triggers prior to experimentation. After exporting the log filemeasure the average energy by specifying start and end times as 0 and 30seconds. Make sure that same number of snapshots are taken during theinterval so that measurements do not deviate by a large value from trial totrial.

3.8.4 Test Case 4: Recording and Playing a Video

Open camera application in the Smartphone and change it to recordingmode. Press the start button and then run the Power Monitor. Record thevideo for 30 seconds, then play it back for the next 30 seconds and stop thePower Monitor. The experimentation process will be automatically stoppedafter 60 seconds as the capture triggers were set accordingly. After exportingthe log file onto the hardisk run the Perl Script by placing in SSH client andthe start and end time in this case are 0 and 60 seconds respectively.

3.8.5 Test Case 5: Bluetooth

The default file chosen for the file transfer is of 931 Kilobytes. Switch on theBluetooth for both the mobiles between which the file has to be transferred.After pairing them, select the file you want to transfer. Run the PowerMonitor and press the send key in mobile. After completing the transferprocess, stop the Power Monitor immediately and export the data. Energyis measured by specifying start and end time as 0 and 40 seconds.

3.8.6 Test Case 6: MP3 Song

The default song that was selected for this test case is from an Indian movie.Play the song in the mobile and wait until the background light is off, thenrun the Power Monitor tool for 30 seconds. Stop it automatically by settingthe capture triggers as mentioned earlier. In this case, start and end timesare 0 and 30 seconds, respectively.

These test scenarios were repeated ten times, the average and standarddeviations of the measurements were tabulated in the next chapter. TelenorSIM cards were used for this purpose.


3.8.7 Test Case 7: YouTube Video

It is the major source of entertainment and education over the Internet.Connect to a wireless network (BTH network in this research) using Wi-Fiand open YouTube from the browser. Make sure that the browser cachesare emptied so that the song or video you fetch doesn’t take the advantageof loading from previous browsed data. Once the video you have searchedis ready for playing, run the Power Monitor and play the video. In our casewe have allowed the run for the whole duration of the video but the energymeasurement was carried out by specifying the start and end times as 0 and90 seconds, respectively.

Repeat the above the test case by accessing the 3G network, i.e. con-necting to HSDPA.

3.8.8 Test Case 8: Browsing Gmail

After connecting to a wireless network browse for Gmail and type the IDand password before logging into the mail, run the Power Monitor and pressthe login button. After checking the mail signout from the mail and stopthe Power Monitor. The measurement period was taken to be 120 secondsi.e. start time is 0 and end time is 120 seconds. Also repeat the samemeasurement for 3G.

3.8.9 Test Case 9: Browsing Facebook

With the increase in Internet usage globally, social connectivity sites arebecoming rapidly popular and one among such sites is Facebook which hasbecome a most important application in Smartphones. Keep ready by typingthe login ID and password of a Facebook ID and before pressing the SignInkey run the Power Monitor. After surfing it, logout and stop the PowerMonitor. In this case, the measurement period was set to 120 seconds. Alsorepeat the measurements for 3G.


3.9 Legend Dialog Box

Figure 3.6: Legend Dialog Box [32]

Figure 3.6 shows the Legend Dialog Box controls, which channels are dis-played and the kind of data shown in the graphs.

3.10 Parameters

The following parameters were analyzed in the experimentation to under-stand the effect of the tasks on the energy consumption.

1. Average voltage: The voltage that is supplied to Smartphone fromthe Power Monitor is the maximum voltage of battery, which is 3.7V. The voltage displayed every second is the average of 5000 samplesgenerated by Power Monitor.

2. Average current: Average current is measured by Power Monitor it-self and is provided in the display whose units can also be adjustedaccording to the requirements of the display. Its unit is milli-Ampere(mA).

3. Average power: The device also measures the average power for theconvenience of measurements. In the log file it is measured as productof voltage and current at that particular instant. It is measured inmilli-Watt (mW).

The values in the log files are instantaneous values of current power andvoltage. Average values are measured by the power monitor for displaypurpose, which are not present in log files. Apart from these we can alsocalculate maximum and minimum values of these parameters in the test caseif required. There also provisions made for changing the time scale of thePower Monitor so as to represent all the values compactly onto the screen,if the time period of a run is very large.

Results

32

Chapter 4

Results

4.1 Introduction

The analysis of experimental data and its results are presented in this sec-tion. Energy consumption measurements for various applications in Smart-phones and browsing tasks using HSDPA and Wi-Fi connectivity are pre-sented in the following sections.

4.2 Energy Calculations

Energy is the amount of work done. SI Units of energy are Joules repre-sented by ’J’. Since the Power Monitor is very sensitive and it generates5000 samples per second, the log files of huge size are dealt with using acode written in Perl. File name, start time and end time are applied as in-put parameters to the Perl code during execution. The cummulative valueof energy consumption of a specific test case is measured by

E =Te

n

n∑i=1

Pi

Pi = P1 + P2 + · · · + Pn

Pn = Power consumed during ’n’th sample.

Te = Time over which the energy needs to be calculated.

= Tend − Tstart

n = Number of samples generated over the time period.

The average value and standard deviations of energy and time are cal-culated using the formulae

33

CHAPTER 4. RESULTS 34

Eavg =1

k

k∑i=1

Ei

Tavg =1

k

k∑i=1

Te,i

Estd =

√√√√ 1

k − 1

k∑i=1

(Ei − Eavg)2

Tstd =

√√√√ 1

k − 1

k∑i=1

(Te,i − Tavg)2

4.3 Energy Measurements of Basic Applications

4.3.1 Voice Call

The Table 4.1 inicates the energy consumption measurements of a voice callfor a duration of 60 seconds. Measurement is started manually after the callis lifted and is stopped automatically after 75 seconds. The extra 15 secondsduration has nothing to do with the measurements as we have allowed someextra duration. Measurements were made during the time period of 0 to 60seconds. The values tabulated are the average values of energy of 10 trialsand standard deviation of energy. Only 10 trails have been choosen (insteadof 30 to 40) due to the significant amount of manual work involved in theprocess.

Table 4.1: Energy Consumption Measurements: Voice CallSony Ericsson Sony Ericsson Sony Ericsson HTC Dream

C902 Elm Xperia

Eavg 48.89 J 52.07 J 37.14 J 49.05 J

Estd 0.64 J 0.64 J 0.92 J 1.64 J


Figure 4.1: Power Consumption of the Smartphones for a Voice Call

Average energy consumption is calculated using the formula describedin section 4.2 and standard deviation of measurements for 10 trials is alsotabulated. It is interesting to observe that Sony Ericsson Xperia which usesAndroid OS that has been recently released into the market is designed insuch a way that it saves 10 -15 Joule of energy on a voice call operated inthe same conditions as compared to the other three phones.


4.3.2 SMS

Table 4.2: Energy Consumption Measurements: SMSSMS 160 char SMS 320 char

Sony Ericsson C902

Eavg 2.37 J 2.38 JEstd 0.02 J 0.01 JTavg 2.29 s 2.29 sTstd 0.02 s 0.01 s

Sony Ericsson Xperia


Sony Ericsson Elm


HTC Dream


Figure 4.2: Power Consumption of the Smartphones for SMS of 160 charac-ters


Figure 4.3: Power Consumption of the Smartphones for a SMS of 320 char-acters

It is interesting to see that Android-based mobiles take less time and powerto send, whereas the other two mobiles took almost three times the amountof time as well as power to send the text of same size. Bringing QoE pa-rameter Response time into picture, users might get irritated if the mobilephone takes too much time to send an SMS. So Android phones can providegood quality of experience in terms of energy consumption and responsetime to users in the case of SMS. In case of other mobiles, If the responsetime of user increases the energy consumption also does and the Quality ofExperience of user degrades.

4.3.3 MP3 Song

Table 4.2 shows the energy consumption measurements of different Smart-phones for a period of 30 seconds.

Table 4.3: Energy Consumption Measurements: MP3 songSony Ericsson Sony Ericsson Sony Ericsson

C902 Elm Xperia

Eavg 10.82 J 10.17 J 16.38 J

Estd 0.27 J 0.19 J 0.73 J


Figure 4.4: Power Consumption of the Smartphones for a MP3 Song

Even though the Table 4.3 shows less amount of energy consumption forall the mobiles when compared to other test cases, it is not constant for allthe songs. It changes from song to song with the intensity of sound andtype of music and the variation is around 4 to 5 Joule. Mostly, people liketo use their Smartphones as MP3 players. For example avoiding the usageof a Smartphone as MP3 player for 15 minutes can save the energy sufficientfor sending 200–300 text messages of 320 characters. HTC dream was notused for experimentation due to technical problems with Micro SD card inthe mobile.

4.3.4 Bluetooth

Table 4.4: Energy Consumption Measurements: BluetoothSony Ericsson Sony Ericsson Sony Ericsson

C902 Elm Xperia

Eavg 16.41 J 12.36 J 25.96 J

Estd 0.39 J 0.6 J 0.67 J


Figure 4.5: Power Consumption of the Smartphones for Bluetooth

From the measurements in Table 4.4 it can be inferred that file is takingsame time from all the mobiles to be transferred but the energy consumedis different. HTC Dream as it doesnot support sending and receiving offiles via bluetooth [38] it is not used for experimentation. An interestingobservation for bluetooth test case is that, From the figure it can be inferedthat time periods for sending same file are not the same. It was observedthat time period is varying as the recieving mobile changes. Time period isconstant only when the file is transfered from the three mobiles under test toa single mobile. Further research can be carried out inorder to understandthis phenomenon.

4.3.5 Recording and Playing

Table 4.5: Energy Consumption Measurements: Recording & PlayingSony Ericsson Sony Ericsson Sony Ericsson HTC Dream

C902 Elm Xperia

Eavg 75.28 J 78.5 J 65.54 J 61.00 J

Estd 0.35 J 1.13 J 1.73 J 0.99 J


Figure 4.6: Power Consumption of the Smartphones for Recording and Play-back

From Figure 4.6 it can be inferred that these Smartphones consume highpower during recording (first 30 seconds in the graph) but for playing back(next 30-60 seconds where power consumption value got down while com-pared to recording) the recorded video they require less power than that ofthe power required for recording. Since a video will be recorded to play itback further, recording and playback were not considered as different testcases. It was also observed during experimentation that as the intensity oflight increases power consumption also increases.

4.3.6 Camera

Table 4.6: Energy Consumption Measurements: CameraSony Ericsson Sony Ericsson Sony Ericsson HTC Dream

C902 Elm Xperia

Eavg 43.31 J 44.46 J 36.56 J 35.94 J

Estd 0.63 J 1.98 J 0.54 J 0.99 J


Figure 4.7: Power Consumption of the Smartphones for Camera application

The values tabulated in this case corresponds to the camera applicationwithout flash. The energy consumption of a camera with flash was found tovary from 5 to 10 Joule, as the flash increases the power rapidly for a shortperiod of time.

4.4 Internet Tasks

Mailing and browsing Facebook has become more prominent nowadays usingSmartphones, which made the manufacturers design applications like mail-box and Facebook for Smartphones. Watching Youtube over mobile phonesis also increasing on rapid pace. As mentioned earlier measurements forInterent tasks were taken only once due to cost and avalability limitations.

4.4.1 Energy Consumption for HSDPA

Table 4.7: Energy Consumption Measurements: HSDPAYouTube Gmail Facebook

(90 s) (120 s) (120 s)

Sony Ericsson C902 108.53 J 102.56 J NA

Sony Ericsson Xperia 61.98 J 103.70 J 98.26 J


Table 4.6 clearly depicts the lesser energy consumption of Android OS incase of HSDPA networks. As C902 does not support downloading of thefile just for logging and reading the mails it consumed 102.56 J where as inXperia a picture is downloaded in same time, but it consumed 1 J higherthan C902. Because of the restrictions on cost, the other two mobiles werenot used for energy measurements of Internet tasks.

4.4.2 Energy Consumption for Wi-Fi

Table 4.8: Energy Consumption Measurements: Wi-FiYouTube Gmail Facebook

(90s) (120 s) (120s)

Sony Ericsson Xperia 55.56 J 68.43 J 69.96 J

Sony Ericsson Green 64.76 J 77.58 J 79.62 J

HTC Dream 127.89 J 91.09 J 123.05 J

From the Table 4.7 it can be inferred that even for Internet applicationsAndroid seems to consume less energy compared with rest of the two. SinceSony Ericsson C902 doesn’t have Wi-Fi capability, measurements were notconducted on the mobile.

4.4.3 Energy Consumption in Sony Ericsson Xperia

Table 4.9: Energy Consumption Measurements: Wi-Fi & HSDPAYouTube Gmail Facebook

(90 s) (120 s) (120 s)

Wi-Fi 55.56 J 68.43 J 69.96 J

HSDPA 61.98 J 103.70 J 98.26 J

This was separately tabulated to show the energy consumption comparisonsfor Wi-Fi and HSDPA at a place for the convenience of readers.

From the measurements tabulated, it is clear that HSDPA consumesmore power than Wi-Fi. So it is better to shift between the connectivity of3G and Wi-Fi depending on the capability and availability of the network.Also the cost for using HSDPA is high compared to Wi-Fi. Since the size ofscreen is very less in Smartphones compared to laptop users may not preferto watch videos over YouTube at a high rate.


4.5 Validation

As explained earlier in section 2.8 the validity of power and energy mea-surements at device level depends on the accuracy of the device under test.So proper care has been taken in this research while calibrating the device.From the standard devaition values tabulted in the results, which are al-most less than 0.5 J in most of the test scenarios one can observe that thestatistical stability is achieved in the results.

In [1] the measurements were conducted on Nokia S60 mobile, for 5 hoursduration of voice call, the energy consumption is measured to be 12304.8 J.The energy consumption values in this research for Sony Ericsson C902 is48.89 J for 60 seconds and if it is assumed to be constant and for 5 hoursit comes to around 14577 J. Even though we are unware of the experimen-tal conditions in the former case, since the values are almost same order ofmagnitude, hereby confirming the validity of the results to certain extent.

In [33] authors have validated the model that they have formulatedagainst the values those were generated by the Power Monitor and foundthat standard deviation and mean error in their values were very small. Themeter was also used to characterize the energy consumption of Wi-Fi andHSDPA networks in the same research. By this the Power Monitor has beenvalidated in earlier researches.

Survey Results

44

Chapter 5

Survey Results

An online survey was conducted with 100 participants from different coun-tries on www.surveymonkey.com. The participants of the survey were in theage group of 20-30 and graduate students from different universities aroundthe world. Among them 74 are male and 26 female participants. The reasonfor choosing the participants in the group between 20-30 is that these peoplewill have idea about the new emerging applications like Gtalk, VoIP, Naviga-tion maps,etc. in Smartphones. Participants were selected ensuring that allof them are Smartphone users. Email IDs of these people were collected andthe survey link was mailed to them.This survey was framed using the mostimportant quality parameters in the context to Smartphone usage, batterylife, and QoE parameters relating to Smartphones and energy consumption.The questions posed to the users are as follows:

1. Device usage: Participants’ choice of the two kinds mobile devices thatthey use mostly in their daily routine.

2. Applications usage: Participants’ choice of applications that they useon their Smartphones regularly.

3. Battery life: Participants’ response to

(a) how often they recharge their mobile phone battery.

(b) how long does their Smartphone battery charging last.

4. Network usage: Participants’ response to

(a) most preferred network that they connect using Smartphone.

(b) most preferred network based on their browsing habits.

5. Willingness: Willingness to change to another network for lower energyconsumption and longer battery life.

6. Quality parameters: Participants’ ranking of parameters that are mostimportant for them while choosing a Smartphone.

45

CHAPTER 5. SURVEY RESULTS 46

5.1 Device Usage

Figure 5.1: Device Usage

Figure 5.1 indicates the usage percentage of various devices.Users’ wereasked to rank themobile devices that they use in their daily life on pri-ority basis. It is interesting to see that next to laptop, the device that ismostly used is a Smartphone followed by Tablet. From this it is obviousthat Smartphone usage has been increasing enormosuly.


5.2 Application Usage

Figure 5.2: Application usage in Smartphones

Figure 5.2 shows the usage percentage of various applications on the Smart-phones. It is surprising to see that most of the users use their Smartphoneas a camera and music player as we found that these applications drain mostof the battery’s energy.


5.3 Battery Life

Figure 5.3: Frequency of charging the user mobile phone

Figure 5.3 indicates the users’ response to the frequency of charging theirmobile phone battery. Almost 49% of the users charge their mobile phonesonce a day. From this, it can be infered that as the applications and featuresare increasing on a Smartphone its battery life is decreasing. Also a directrelation between QoE and energy consumption can be observed. As theenergy consumption increases battery life and backup (total number of hoursfor which the charging of a mobile losts) decreases leading to degradation inQoE of users.


5.4 Battery Backup

Figure 5.4: Battery Backup of users’ Smartphones

Figure 5.4 indicates the time duration for which the charging of a Smart-phone lasts. It is interesting to find that 21% of the users do not get abattery backup of more than 12 hours. Only 30% of the users find theirSmartphone battery to last for 24 hours.

5.5 Network Usage

Figure 5.5: Network preference based on connectivity

The statistics in Figure 5.5 indicate that most users prefer to connect toWi-Fi based on availability (if it is available) and connectivity (if it is good


and performing well).

Figure 5.6: Network preference based on browsing habits

Statistics shown in Figure 5.6 indicates that 72 % of users find it moreconvenient to use Wi-Fi than 3G for browsing.

Table 5.1: Comparison of Network Usage and User PreferenceNetwork % of usage % of preference % of change

Wi-Fi 50.3 % 70.1 % 20.2% increase

3G 43.3 % 25.8 % 17.5 % decrease

Other 6.4 % 4.1 % 2.1 % decrease

Table 5.1 gives comparison between network usage and preference basedon users browsing habits.The % of change column shows the difference be-tween usage and preferences, which denotes the demand of the network. SoWi-Fi has more demand among the users when compared to HSDPA. SinceHSDPA is more energy consuming and costly users prefer to use Wi-Fi.


5.6 Willingness

Figure 5.7: Willingness to use another network

From Figure 5.7, one of the interesting findings from the survey was thatmany users are willing to use another type of network if it consumes lessenergy and gives more battery life. The percentage of users in this categoryis as high as 81%.

5.7 Quality Parameters

Table 5.2: Quality ParametersParameter % of users

Cost 33.7 %

Battery life 49.5 %

Features and Applications 37.5 %

Internet connectivity 27.4 %

Touch Screen 21.9 %

Screen Size 16.8%

Table 5.2 indicates the percentage of users those feel the parameter tobe most important. Each user was asked to give their order of priority forall the 6 paramters ranging from most important to least important. It isinteresting to see that to almost 50% of users battery life is the most vitalfactor in choosing a Smartphone.


5.8 Summary

To summarize the survey, Smartphones are next to Laptops and their usagehas been increasing rapidly. Users’ prefer to use their Smartphones mostlyfor entertainment, browsing purpose and communicating via text messages.Wi-Fi is the most preferred and used network due to availability and thelimitations on cost for HSDPA. The battery charging of most of the userslast less than 24 hours which makes them to recharge their mobile phonesalmost every day. Finally users are willing to change to a network otherthan HSDPA and Wi-Fi (if available) if it reduces the energy consumptionand saves the battery life.

Chapter 6

Conclusions

6.1 Summary

In this research, a cost effective Mobile Device Power Monitor for measuringthe energy consumption of applications in Smartphones was identified. Amethodology for measuring the consumption of mobile devices using a ded-icated hardware has been proposed. A detailed analysis was carried out onthe energy consumption of basic applications in Smartphones. Keeping inview the interests of the users, Power and energy consumption of various ap-plications in Smartphones are compared. Based on the availability, mobilephones with two different operating systems Android and Java, were usedfor this research. Energy consumption of applications in Wi-Fi & HSDPAnetworks were compared based on their support in the Smartphones used forthe research. It was found that HSDPA consumes more energy than Wi-Fi.

This research was successful in establishing a hardware based method-ology i.e. identifying the Power Monitor and creating a test bed that canprovide reliable measurements of energy consumption in Smartphones. Thismethod is more advantageous than softwared based measurements as thesoftware based measurements derive power from measuring the voltage inwhich this relationship is not necessarily modeled in a convincing way. Themeter used gives direct reading of power which is the product of voltage andcurrent readings at every instant in the log files. The high sampling rate ofthe Power Monitor increases the precision of voltage and current readingsby recording the minor changes as well.

From the analysis it was observed that energy consumption in mobilephones is influenced by the type of OS used by them. In the scenarios pre-sented in the results section, Android is found to be more benificial as itsaves energy when compared to the other OS. The manufacturer that candevelop better OS for Smartphones is more likely to play a vital role in mo-

53

CHAPTER 6. CONCLUSIONS 54

bile market.

As pointed out earlier, network operators have an interest of increasingbattery life of users phones. So this kind of research will help them in analyz-ing the amount of energy consumed for various services they are providing.To connect to a particular type of network is completely independent of thenetwork operator but it is dependent on user about the capability of thatnetwork, availability and QoE issues. So the results obtained through thisresearch will help the manufacturers to analyze user preference to particulartype of network, the services they use and parameters that users considerto be more important while choosing a Smartphone.

6.2 Research Questions and Answers

This research is mainly intended to answer the following research questions.

Regarding the first research question RQ1 Is there a methodology to mea-sure the energy consumption of a mobile phone battery reliably in real timeenvironment. From the literature survey it was found that in [1] a meter ismentioned which is used to carry out a similar type of research but dealingwith switching and handoffs on a Nokia N95 mobile. No proper methodol-ogy regarding the connections and measurements were presented in previousresearches. Mobile Device Power Monitor was identified and a test bed wasdesigned to measure the energy consumption of battery in Smartphones.This methodology is reliable because the Mobile Device Power Monitor thatis used in the research is very sensitive towards sampling rate and generatespower consumption values directly in the log files. But the meters used inprevious researches for measuring the energy are used as multimeters whichin turn measure voltage and current values but not power. This method re-duces the computational complexity in measuring the energy by calculatingthe power values in log files.

The second research question RQ 2 Does the energy consumption de-pend on the type of OS used in the mobile phone. In this research, due toavailability limitations only effects of two operating systems were consideredand it was found that energy consumption varies enormously with type ofoperating system used in the mobile. Linux based Android OS exhibitedless energy consumption when compared to Java powered mobiles.

The last research question is RQ 3 How can we relate QOE and energyconsumption in mobile devices. Mobile Device Power Monitor tool used inthis research, the proposed test bed and the test cases clearly depict thepossibility of experimentally evaluating the energy consumption of mobile

CHAPTER 6. CONCLUSIONS 55

phone battery. QoE of users can be obtained by taking their opinion throughthe survey and analysis both the results from experimentation and surveyboth can be related. Response time of user in SMS test case and batterybackup, battery life Quality paramters in the survey are some of the in-stances where they are related to energy consumption in this research. TheQoE survey mainly helps the network operators to have an idea about thepreference and usage of networks by users and their opinion about exsist-ing network. Factors that limit the usage of mobile devices were identifiedthrough the literature survey.

6.3 Future Work

This thesis aims at establishing a hardware based set up that can providereliable measurements of energy consumption in various Smartphones. Dueto time and cost constraints only four mobiles operating with two differentoperating systems were used in this research. In future, research can bedone on more Smartphones with different operating systems so as to studythe effect of OS on energy consumption in depth. In future the number oftest cases can also be increased. Few trials were conducted on Wi-Fi andHSDPA interfaces and only few applications were analyzed so future scopecould be analyzing many applications in more networks if available. Due totime limitations very few parameters were considered for experimentationbut future research is recommended on carrying out a detailed analysis onthe effect of various factors on energy consumption. To understand the effectof signalling strength on these measurements it is recommended to carry outthe same research in a controlled environment available in BTH.

In this research experimentation was performed manually. In futurethere is a scope to automate the test cases by using some sort of scriptingto control the applications in Smartphones. This research is conducted in asingle location, future research can be carried out in various locations withdifferent signal strengths and network speeds and compare the effect of thesevariations on energy consumption. A deeper study may also be carried onto drill down into the reasons for variations in energy consumption withdifferent parameters and network technologies. More over because of highresolution in time, Energy consumption modelling of various applications inSmartphones can be carried out as a future work.

Appendix

56

Appendix A

Experiments and Analysisdata

A.1 Hardware and Software Requirements for theWorkstation

A dedicated workstation is required to be used with the Mobile Device PowerMonitor [32] to achieve the optimal performance and results.

1. Microsoft Windows XP SP2, Windows Vista and Windows 7 is sup-ported.

2. 1 GHz 32-bit (x86) or 64-bit (x64) processor.

3. 1 GB of system memory.

4. 40 GB hard drive with at least 15 GB of available space.

5. Full Speed USB 1.1/USB 2.0 integrated chipset or PCI/PCI Expressadd in card. USB Hubs should not be used with the Mobile DevicePower Monitor.

A.2 Data Exporting Features of Power Monitor

The data exporting features of the Power Monitor allows the user to savedata for the following:

1. The entire power measurement run.

2. If any data is selected with the mouse, the selected data is exported.

3. If no data is selected with the mouse, then the data that is displayed.

57

APPENDIX A. EXPERIMENTS AND ANALYSIS DATA 58

The Power Tool software can export to the file formats shown in the followingtable.

Table A.1: File Formats [32]File format Description

.PT4 Binary data in exactly the same format that the Power Mon-itor creates, this is compatible with the current version ofthe protocol specification.

.CSV Comma-Separate Values. A common format that can beused to import into spreadsheet software. The Power Mon-itor saves only what is recorded in the current trace.

.DCF A common format for exporting test data.

All of these formats, when saved, are saved at the maximum time reso-lution, regardless of the Capture Settings.

A.3 Average Power Consumptions Values of 10Trials for Basic Applications

A.3.1 Sony Ericsson C902

Table A.2: Sony Ericsson C902: Basic ApplicationsTrial.No Voice Call MP3 Song Bluetooth Recording and Playback Camera

(mW) (mW) (mW) (mW) (mW)

Trial1 800.37 328.97 405.07 1227.47 1437.45

Trial 2 827.13 392.38 414.23 1229.07 1442.11

Trial 3 818.52 312.09 392.67 1240.54 1423.18

Trial 4 821.5 392.93 409.57 1229.73 1410.10

Trial 5 828.72 350.03 410.30 1287.77 1432.58

Trial 6 796.00 348.03 415.75 1295.09 1472.25

Trial 7 796.84 349.90 425.66 1296.15 1467.91

Trial 8 824.91 347.98 424.81 1219.56 1466.77

Trial 9 835.00 348.78 408.89 1225.95 1444.51

Trial 10 801.22 350.71 423.25 1297.71 1445.87


A.3.2 Sony Ericsson Xperia

Table A.3: Sony Ericsson Xperia: Basic ApplicationsTrial.No Voice Call MP3 Song Bluetooth Recording and Playback Camera


Trial 1 627.38 587.09 627.88 1062.83 1215.22

Trial 2 625.28 536.73 642.19 1061.72 1214.11

Trial 3 621.70 548.78 634.16 1099.48 1213.56

Trial 4 599.80 553.56 653.19 1124.80 1229.90

Trial 5 646.14 507.44 643.09 1113.33 1244.66

Trial 6 616.70 570.86 652.80 1123.70 1215.69

Trial 7 613.08 550.30 675.63 1078.98 1196.99

Trial 8 594.72 507.78 640.08 1064.23 1226.94

Trial 9 627.38 548.20 627.89 1078.65 1238.54

Trial 10 621.22 550.69 638.74 1119.84 1189.52

A.3.3 Sony Ericsson Elm

Table A.4: Sony Ericsson Green: Basic ApplicationsTrial.No Voice Call MP3 Song Bluetooth Recording and Playback Camera


Trial 1 861.96 270.37 267.26 1283.20 84.6

Trial 2 885.93 275.22 294.89 1273.69 87.6

Trial 3 860.50 310.59 302.44 1322.17 85.2

Trial 4 870.40 323.48 318.15 1325.60 84

Trial 5 850.45 308.82 315.34 1298.78 84

Trial 6 872.65 299.53 311.67 1312.86 84.6

Trial 7 879.24 310.63 292.80 1319.65 85.2

Trial 8 872.04 319.83 319.83 1323.50 87.6

Trial 9 870.76 325.46 302.36 1316.14 84

Trial 10 855.70 308.74 303.56 1331.12 84


A.3.4 HTC Dream

Table A.5: HTC Dream: Basic ApplicationsTrial.No Voice Call Recording and Playback Camera

(mW) (mW) (mW)

Trial 1 810.43 980.64 1177.16

Trial 2 781.52 988.80 1180.66

Trial 3 796.11 1010.71 1183.92

Trial 4 802.73 1012.83 1194.45

Trial 5 846.45 1023.49 1201.91

Trial 6 856.27 1026.56 1197.26

Trial 7 830.30 1013.53 1203.59

Trial 8 824.91 1034.18 1235.35

Trial 9 830.30 1015.01 1203.83

Trial 10 818.22 1025.67 1182.64

A.4 SMS Growth

Figure A.1: SMS Growth in recent years [34]

Figure A.1 shows the growth of SMS which is taken from ICT facts andfigures[34]. Based on the statistics presented in [34] and keeping in view


that SMS is generating in different countries, so more attention was paid toanalyze the SMS test case.

A.4.1 Analysis of SMS for Sony Ericsson C902

Table A.6: Energy Consumption Measurements: SMSSMS 160 char SMS 320 char

Trial 1E 2.39 J 2.39 JP 1041.88 mW 1037.41 mWT 2.30 s 2.30 s






Trial 7E 2.39 J 2.39 JP 1039.26 mW 1037.41 mWT 2.30s 2.30s

Trial 8E 2.37 J 2.39 JP 1037.66 mW 1028.13 mWT 2.30s 2.30s




A.4.2 Analysis of SMS for Sony Ericsson Xperia







Trial 6E 0.88J 0.82JP 1070.91 mW 1092.45 mWT 0.82 s 0.74 s






A.4.3 Analysis of SMS for Sony Ericsson Elm













A.4.4 Analysis of SMS for HTC Dream













A.5 Specifications and Features of Smartphones

A.5.1 Specifications of Sony Ericsson C902

Table A.10: Specifications of Smartphones: Sony Ericsson C902Feature Description

General2G Network GSM 850 / 900 / 1800 / 19003G Network HSDPA 2100 - C902i only

DisplayType TFT, 256K colorsSize 240 x 320 pixels, 2.0 inches

Data3G HSDPA, 3.6 MbpsWLAN Not supportedBluetooth v2.0 with A2DP

Camera Primary 5 MP, 25921944 pixels, autofocus, LED flash

FeaturesMessaging SMS, MMS, Email,Push Email, Instant MessagingBrowser WAP 2.0/HTML (NetFront), RSS reader

BatteryStandard battery, Li-Po 930 mAh (BST-38)

Stand-by Up to 400 h (2G) / Up to 360 h (3G)Talk time Up to 9 h (2G) / Up to 4 h (3G)

A.5.2 Specifications of Sony Ericsson Elm

Table A.11: Specifications of Smartphones: Sony Ericsson ElmFeature Description

General2G Network GSM 850 / 900 / 1800 / 19003G Network HSDPA 2100 HSDPA 900 / 2100

DisplayType TFT, 256K colorsSize 240 x 320 pixels, 2.2 inches

Data3G HSDPA, 7.2 Mbps; HSUPA, 1.8 MbpsWLAN Wi-Fi 802.11 b/g, DLNABluetooth v2.1 with A2DP, EDR

Camera Primary 5 MP, 2592 x 1944 pixels, autofocus, LED flash

Featuresmessaging SMS (threaded view), MMS, Email, Push Email, IMBrowser WAP 2.0/WAP 2.0/HTML (NetFront), RSS reader

BatteryStandard battery, Li-Po 1000 mAh (BST-43)

Stand-by Up to 336 h (2G) / Up to 424 h (3G)Talk time Up to 4 h 30 min (2G) / Up to 3 h 40 min (3G)


A.5.3 Specifications of Sony Ericsson Xperia X8

Table A.12: Specifications of Smartphones: Sony Ericsson Xperia X8Feature Description

General2G Network GSM 850 / 900 / 1800 / 19003G Network HSDPA 900 / 2100 HSDPA 850 / 1900 / 2100

DisplayType TFT capacitive touchscreen, 16M colorsSize 320 x 480 pixels, 3.0 inches

Data3G HSDPA, 7.2 Mbps; HSUPA, 2 MbpsWLAN Wi-Fi 802.11 b/gBluetooth v2.1 with A2DP

Camera Primary 3.15 MP, 2048x1536 pixels,

FeaturesOS Android OS, v1.6 (Donut), upgradableCPU 528 MHz ARM 11 processor, Adreno 200 GPUMessaging SMS (threaded view), MMS, Email, Push email, IMBrowser HTML

Battery

Standard battery, Li-Po 1200 mAhStand-by Up to 446 h (2G) / Up to 476 h (3G)Talk time Up to 4 h 45 min (2G) / Up to 5 h 40 min (3G)Music play Up to 23 h 40 min

A.5.4 Specifications of HTC Dream

Table A.13: Specifications of Smartphones: HTC DreamFeature Description

General2G Network GSM 850 / 900 / 1800 / 19003G Network HSDPA 2100 HSDPA 1700 / 2100 - American version

DisplayType TFT capacitive touchscreen, 65K colorsSize 320 x 480 pixels, 3.2 inches

Data3G HSDPA, 7.2 Mbps; HSUPA 2 MbpsWLAN Wi-Fi 802.11 b/gBluetooth v2.0 with A2DP, headset support only

Camera Primary 3.15 MP, 2048x1536 pixels, autofocus

FeaturesOS Android OS, v1.6 (Donut), upgradableCPU 528 MHz ARM 11 processor, Adreno 130 GPUMessaging SMS, MMS, Email, Instant MessagingBrowser HTML

BatteryStandard battery, Li-Ion 1150 mAh

Stand-by Up to 406 hTalk time Up to 5 h 20 min


A.6 Miscellaneous

Figure A.2: Various parameters for playing a game for 300 s in Sony EricssonC902

We find very often, people playing wide variety of games in their mobilephones which is considered to be one of the major sources of entertainment.The above power profile gives an idea of how the power is being consumedwhile playing a game continuously.

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