Energy Consumption of Mobile YouTube: Quantitative Measurement and Analysis

Yu Xiao, Ramya Sri Kalyanaraman, Antti Ylä-JääskiHelsinki University of Technology, Finland

yuxiao@cc.hut.fi

Outline

• Introduction •Experiment Setup•Experimental Results & Analysis•Future Work

Introduction

•Mobile Devices▫Functions vs. Energy Consumption▫Multimedia, Internet, Context-aware…

•Online video sharing

Introduction

•YouTube▫Largest online video sharing website▫Support access from mobile devices

Website: m.youtube.com

Concerned Techniques

•Progressive download▫HTTP/TCP▫No resource reservation▫Media server pushes data to the clients as fast as

possible▫Client starts playback once enough data has been

downloaded

DownloadDownloadPlayback Playback

Research Questions

•What are the factors that influence energy consumption?▫Download Technology

Progressive download vs. Traditional TCP download-and-play

▫Network Access Technology WCDMA vs. WLAN 802.11g

▫Playback settings Storage media used (Phone memory vs. External

flash drive vs. Cache)

Experiment Setup

• Nokia N95 ▫Symbian 60 3rd FP1▫WCDMA, WLAN▫BL-5F 950mAh 3.7V

• Nokia Energy Profiler Monitor voltage, current, temperature

▫Mobile YouTube Clients▫emTube: download▫YouTube for Mobile: upload

Network Settings•WCDMA(3G)

▫Internet subscription with both downlink and uplink bandwidth of 384kbps

•WLAN▫LINSYS WAP 200 Wireless-G Access Point

connected to campus InternetMax Data Rate

54Mbps Beacon Interval

100ms

Downlink 5455kbps Uplink 1429kbps

RTT 92ms U-APSD Disabled

Progressive download vs. Traditional TCP download –and-play

WCDMA WLAN

WCDMA vs. WLAN

Progressive Download Upload

Playback

1.452W 1.426W 1.451W

Default system

▫Concerned factors▫Energy Profiling Software▫System Processes▫Backlight▫Cell States of WCDMA ▫Idle state of WLANState WCDMA WLAN Power(Watt)

1 Disabled Disabled 0.270

2 Disabled Idle 0.376

3 CELL_DCH Disabled 0.741

4 CELL_PCH Disabled 0.282

5 CELL_FACH Disabled 0.549

WCDMA Cell States

WCDMA Cell States

WCDMA Cell States

Progressive download via WCDMA

Progressive download via WCDMA

Progressive download via WCDMA

Progressive download via WCDMA

Calculation

•Precondition▫Total energy consumption consists of two

parts, namely, mobile YouTube and default system

▫Energy consumption of playback from cache (replay) equals to that of playback during progressive download

•Expected quantity▫Energy consumption of download,

playback and default system in each phase

Argument -1

•Progressive download via WLAN is more energy-efficient than using WCDMA

•Energy consumption during progressive download can be separated into download , playback and default system

playback download default system

WLAN 275.079J 57.448J 91.368J

WCDMA 275.079J 159.748J 175.563J

Argument-2

•Network Transmission▫The data rate is not limited by local

processing capability ▫Traffic regulated by YouTube server

•Energy consumption of playback ▫Error caused by temperature in limited

range can be ignored▫Difference caused by loading video into

cache among media used

Future work

•Power modeling of progressive download▫Power measurement in public WLAN▫Power vs. data rate▫Energy vs. traffic distribution

•Energy efficient adaptation to network conditions▫SNR-based dynamic adaptation

Thanks!

Public WLAN

Progressive download

Phase Playback Download Default system

1 0 1.240W 4.960J 0.376W 1.504J

2 1.137W 122.751J

0.486W 52.488J 0.376W 40.608J

3 1.154W 152.328J

0 0.376W 49.256J

Total 1.156W 275.079J

0.513W 57.448J 0.376W 91.368J

WLAN

Phase Playback Download Default system

1 0 0.940W 9.400J 0.741W 7.410J

2 1.150W 231.227J

0.748W 150.348J

0.741W 148.941J

3 1.154W 43.852J 0 0.701W 26.622J

Total 1.151W 275.079J

0.757W 159.748J

175.563J

WCDMA

Establishment of TCP Flash Video Download

Media Server

Downlink in WLAN

Local playback