Application layer based dynamic bandwidth allocation mechanism in heterogeneous

networks

Speaker: Kai-Wei PingAdvisor: Prof Dr. Ho-Ting Wu

2014/06/23

Outline

• Introduction• Impact of TCP on Progressive Video Delivery• Difference in Behaviors between Mobile and

Fixed Users• 系統架構及說明• 實驗

Introduction

• Video streaming services via best-effort networks such as the Internet and mobile networks are growing rapidly and will generate massive traffic in the next several years

Network traffic V.S. Video streaming

• Downloading unused video data generates a large amount of unnecessary network traffic.

• 60% of YouTube video sessions are aborted before users watch them for no more than 20% of the video duration, and these abortions cause 25% to 39% of data to be unnecessarily transferred

Impact of TCP on Progressive Video Delivery

Impact of TCP on Progressive Video Delivery

• Developed a simulation model using the OMNeT++’s INET framework

• Vary the bandwidth of the backhaul link (), and analyze its effect on the data throughput experienced by each UE and the state of the playout buffer

Impact of TCP on Progressive Video Delivery

Simulation parametersFile size 100 Mbytes

MSS(TCP) 1452 bytes

Link parameters

Bandwidth VariableDelay 20 msPER 0.00001

Bandwidth 4 Mb/sDelay 5 msPER 0.0005

Bandwidth 2.5 Mb/sDelay 5 msPER 0.0005

Impact of TCP on Progressive Video Delivery

Simulation parameters

Link parametersBandwidth 1.2 Mb/s

Delay 5 msPER 0.0005

Playback rate (b/s)2 Mb/s2 Mb/s1 Mb/s

Impact of TCP on Progressive Video Delivery

Impact of TCP on Progressive Video Delivery

Impact of TCP on Progressive Video Delivery

Difference in Behaviors between Mobile and Fixed Users

• Give a comparison of viewing behaviors of mobile and fixed immobile users

• The viewing completion proportion of video contents stratified in three classes of video lengths: 0~10 min, 20~30 min, and 40~50 min

• Two types of access to PPTV: standalone PC client and mobile application

Dataset Description

• PPTV is currently the largest commercial online video service in China and the largest media platform worldwide, offering both online live and on-demand video broadcasting

• The dataset we have used came from a comprehensive measurement of PPTV, also referred to as PPLive

Difference in Behaviors between Mobile and Fixed Users

Difference in Behaviors between Mobile and Fixed Users

Difference in Behaviors between Mobile and Fixed Users

系統架構6 Mb/s

3 Mb/s

1 Mb/s

Traffic control

架構說明• 對個別頻寬的限速，皆在 server 端計算，

client 端本身並不參與任何決策• Server 端收集 client 端傳回來的資訊，加以計算推論出 client 端的網路環境，選擇不影響 client 端的 QoE ，且能提高整體的網路流量的使用率的網路速度，加以控制• Server 端利用 Linux traffic control tool ，可針對個別的 IP 進行流量的控制

QoE 判斷標準• 對 client 端而言，當使用瀏覽器點擊欲觀看的影片的網址時，瀏覽器能夠快速從

server 端下載影片並啟動影片，且瀏覽器的 buffer 量足夠 client 持續觀看影片，而不會發生影片中斷，須等瀏覽器從 server 端下載更多影片量方能播放，以此當作基準

Linux traffic control

• Traffic control is the name given to the sets of queuing systems and mechanisms by which packets are received and transmitted on a router.

• This includes deciding which (and whether) packets to accept at what rate on the input of an interface and determining which packets to transmit in what order at what rate on the output of an interface.

Linux traffic control

實驗• 瀏覽器播放技術測試• 頻寬測試• 多使用者連線測試

實驗環境• 測試伺服器： 140.124.182.231 (ubuntu 12.04.4

Apache 2.22)• 測試影片： http://140.124.182.231/video/

100_2012-05-12_22-00-00.mp4 (559MB)( 位元率 : 645Kbps)

• 網路環境： ntutcc• Chrome 版本： 35.0.1916.114 m• FireFox 版本： 29.0.1• IE 版本： 11.0.9600.17107

瀏覽器播放技術測試 _ChromeGoogle Chrome

Jwplayer 播放中

暫停播放

瀏覽器播放技術測試 _FireFox

FireFox

Jwplayer 播放中

暫停播放

瀏覽器播放技術測試 _IEIE

Jwplayer 播放中

暫停播放

重點觀察• 每個瀏覽器對串流影音處理的動作皆不一樣• 針對瀏覽器對影音串流的處理，即使在不同的電腦，表現上也一致• 瀏覽器需求頻寬跟播放的技術無關，不論是 jwplayer 還是 HTML5 ，瀏覽器的表現皆一致

實驗環境• 測試伺服器： 140.124.182.231 (ubuntu

12.04.4 Apache 2.22)• 測試影片： http://140.124.182.231/video/

100_2012-05-12_22-00-00.mp4 (559MB)( 位元率 : 645Kbps)• 網路環境： ntutcc 、有線• FireFox 版本： 29.0.1

頻寬測試 _有線網路Wire network

一台筆電

兩台筆電

頻寬測試 _有線網路

兩台筆電 + 一台桌電

頻寬測試 _wifiWireless network

一台筆電

兩台筆電

頻寬測試 _wifi

(Stop)

• 有線網路環境裡，一台電腦開啟 FireFox 瀏覽器向伺服器要求串流連線時的頻寬將近11.7MB/ 秒，即使增加連線的數量後，最大頻寬也依然是 11.7MB/ 秒

• 無線網路環境裡，只有一台電腦向伺服器要求串流連線時的頻寬將近 2MB/ 秒左右，即使增加連線的數量後，最大頻寬也依然是 2MB/ 秒

重點觀察

實驗環境• 測試伺服器： 140.124.182.231 (ubuntu

12.04.4 Apache 2.22)• 測試影片： http://140.124.182.231/video/

100_2012-05-12_22-00-00.mp4 (559MB)( 位元率 : 645Kbps)• 網路環境： ntutcc 、有線• FireFox 版本： 29.0.1

多使用者連線測試6_user_ 2_mobile_2_notebook_wireless

多使用者連線測試Port : 19375(BLACK) 4.134 (Mb/s)

Port : 55493 (RED) 4.278 (Mb/s)

Port : 17898 (GREEN) 1.708 (Mb/s) Port : 9037 (BLUE) 0.047 (Mb/s)

168 (BLUE) 89.790 (Mb/s) 190(PINK) 1.349 (Mb/s)

重點觀察• 在異質網路下，根據測試的結果，發現了頻寬分配不均的情況

38

References

• F.Z. Yousaf, M. Liebsch, A. Maeder, S. Schmid, ” Mobile CDN enhancements for QoE-improved content delivery in mobile operator networks, ” IEEE Network, vol. 27, pp. 14-21, March-April 2013.

• Y. Sun, Y. Guo, Z. Li, J. Lin, G. Xie, X. Zhang and K. Salamatian, ” The Case for P2P Mobile Video System over Wireless Broadband Networks: A Practical Study of Challenges for a Mobile Video Provider, ” IEEE Network, vol. 27, pp. 22-27, March-April 2013.

References

• http://www.tldp.org/HOWTO/Traffic-Control-HOWTO/index.html