串流影音服務日益盛行，但其透過開放式網路傳輸視音訊內容以致於難以掌握服務的品質 (QoS)。因此，近年來開始有研究意圖將用戶感受量化作為體驗指標，以便衡量用戶影音服務體驗品質 (QoE)，例如由財團法人電信訓練中心提出的客觀 QoE 模型「視訊平均意見分數 (video Mean Opinion Score; vMOS) 便是一個例子，其將串流服務中的視訊解析度、初始緩衝時間與卡頓情況等綜合因素轉換為單一 vMOS 量化指標 (最低1分至最高5分)，並揭露了部份的效度量測結果與場測應用案例。
為了能更全面地檢視 vMOS 指標的可用性，本論文透過在 Android 系統開發 App 實作了 vMOS 指標量測工具，並對該量測工具進行完整的信度與效度分析驗證。其中，信度驗證部份共執行了前後兩週的長時間測試，由相關數據統計出再測信度量測結果；效度驗證部份共安排150位使用者 (涵蓋不同性別與年齡) 進行視訊服務體驗品質量測實驗，依據不同使用者族群統計出三種效度量測結果︰整體實驗人員校標效度、性別分類校標效度與年齡分層校標效度。
另外，為了觀察 vMOS 指標是否能適當地反應網路傳輸性能 (對網路營運商而言具有重要意義)，本論文也設計了一個可控 QoS 的區網實驗環境，進一步分析 vMOS 指標量測結果與個別 QoS 參數之間的關聯性，其中QoS參數包含Throughtput、Packet Loss 與 Delay 等測項。

Streaming services have been more and more popular. However, it is difficult to control the quality of the service (QoE) because the audio/video contents are transmitted through an open network. Recently, researches have been reported to quantify user experience about streaming services as certain indices in order to measure the quality of experience (QoE). For example, the objective QoE model “video Mean Opinion Score (vMOS)” proposed by the Telecom Technology Center (TTC) is one of them. The factors of video resolution, initial buffering time and stalling conditions of a streaming service are converted into a single quantitative index (minimum 1 point to maximum 5 points). TTC then reveals partial results about the validity verification and field tests of the vMOS index.
In order to completely examine the availability of the vMOS index, this paper implements an App-based vMOS index measurement tool on the Android system, and conducts a complete reliability and validity verification of the measurement tool. For the reliability verification, a test continued in a two-week duration to estimate the retest reliability; for the validity verification, 150 users (covering different genders and ages) joined the experiment to estimate the calibration validities based on different user groups: all users, gender-clustered users and age-clustered users.
In addition, in order to observe whether the vMOS index can properly reflect the network transmission performance (which is interesting to network operators), this paper also set up a QoS-configurable local area network as the experimental environment where the relations of the vMOS index to individual QoS parameters (throughput, packet loss, and delay) were studied.

摘要 i
Abstract iii
誌謝 v
目錄 vi
圖目錄 ix
表目錄 x
第一章 緒論 1
1.1前言 1
1.2研究背景與動機 1
1.3研究目的 3
1.4相關研究 4
1.4.1 QoS的定義 4
1.4.2 QoE的定義 5
1.4.3主觀的QoE 7
1.4.4客觀的QoE 8
1.4.5量測工具性能說明 8
1.4.6可靠性 (信度) 9
1.4.7有效性 (效度) 10
1.5視訊來源 12
1.6困難與挑戰 12
1.7論文架構 13
第二章 問題描述與信效度驗證流程 14
2.1問題描述 14
2.2信效度驗證流程 14
2.3行動裝置簡介 15
第三章 量測工具之說明與信效度驗證 18
3.1量測工具之說明 18
3.2 vMOS參數計算 20
3.3開發環境介紹 21
3.4連續 14 日同一時段定點測試結果之穩定性分析 22
3.5效標效度分析說明 24
3.5.1整體實驗人員校標效度 25
3.5.2性別分類校標效度 27
3.5.3年齡分層校標效度 30
第四章 vMOS與QoS關聯性探討 35
4.1網路環境架設 35
4.2 QoS網管功能交換器 36
4.3影片源特性分析 37
4.4 vMOS與QoS之關聯性分析說明 38
4.4.1 vMOS與Throughput之關聯性 39
4.4.2 vMOS與Packet Loss之關聯性 40
4.4.3 vMOS與Delay之關聯性 42
第五章 結論 44
參考文獻 46
附錄A 量測工具之用戶端 App 操作說明 51
A.1 操作介面簡介 51
A.2 主要功能介紹與測項執行順序策略 51
A.3 首次安裝設定說明 52
A.4 測試操作說明 52
A.5 歷史紀錄查詢 54
A.6 進階設定 57

[1]Kantar Insights Division 凱度洞察台灣/ LifePoints, “台灣OTT市場隨選影視戰況分析” , [Online]. Available:
https://www.brain.com.tw/news/articlecontent?ID=48759#8scQoDZp
[2]Cisco, “Cisco visual networking index: Forecast and methodology, 2016 – 2021,” Sept. 15, 2017. [Online]. Available:
https://www.cisco.com/c/en/us/solutions/collateral/service-provider/visual-networking-index-vni/complete-white-paper-c11-481360.html
[3]SamKows, “SamKnows test methodology (Document reference: SQ301-005-EN),” Feb. 2015.
[4]BEREC, “Net neutrality regulatory assessment methodology,” BoR (17) 178, May 2017.
[5]財團法人電信訓練中心電子會報-物聯網遠距視訊應用之vMOS評測平台_檢技暨網通技術組. [Online]. Available:
https://epaper.ttc.org.tw/info.aspx?aQBkAA2=NwA1AA2&bgBvAA2=NQAyAA2
[6]Apple Inc., “HTTP live streaming technical overview 2013”, [Online]. Available:
https://developer.apple.com/library/ios/documentation/networkinginternet/conceptual/streamingmediaguide/Introduction/Introduction.html
[7]DASH Industry Forum, “For promotion of MPEG-DASH 2013”, [Online]. Available: http://dashif.org
[8]Adobe Systems Inc., “HTTP dynamic streaming 2013”, [Online]. Available:
http://www.adobe.com/products/hds-dynamic-streaming.html
[9]ITU-T Rec. E.800, “Terms and definitions related to quality of service and network performance including dependability,” Aug. 1994.
[10]E. Crawley et al., “A framework for QoS-based routing in the Internet,” IETF RFC 2386, Aug. 1998.
[11]ITU-T, “Definition of experience (QoE),” International Telecommunication Union, Liaison Statement, Ref: TD 109rev2 (PLEN/12), 2007.
[12]M. Edo, et a1., “A QoE management system for ubiquitous IPTV devices,” Proc. International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies, 2009.
[13]R. Serral-Gracià et al., “An overview of quality of experience measurement challenges for video applications in IP networks”, Proc. International Conference on Wired/Wireless Internet Communications, Luleå, Sweden, June 1-3, 2010, pp. 252-263.
[14]S. S. Krishnan and R. K. Sitaraman, “Video stream quality impacts viewer behavior: inferring causality using quasi-experimental designs,” IEEE/ACM Trans. on Networking, Dec. 2013
[15]ITU-T Rec. P.910, “Subjective video quality assessment methods for multimedia applications,” 2000.
[16]ITU-T Rec. J.343.5, “ Hybrid-FRe objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a full reference signal and encrypted bitstream data,” 2014.
[17]ITU-T Rec. J.343.6, “Hybrid-FR objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a full reference signal and non-encrypted bitstream data,” 2014.
[18]ITU-T Rec. J.343.3, “Hybrid-RRe objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a reduced reference signal and encrypted bitstream data,” 2014.
[19]ITU-T Rec. J.343.4, “Hybrid-RR objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a reduced reference signal and non-encrypted bitstream data,” 2014.
[20]ITU-T Rec. J.343.1, “Hybrid-NRe objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of encrypted bitstream data,” 2014.
[21]ITU-T Rec. J.343.2, “Hybrid-NR objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of non-encrypted bitstream data,” 2014.
[22]I. Ketykó et al., “QoE measurement of mobile YouTube video streaming,” Proc. Workshop on Mobile Video Delivery, Firenze, Italy, Oct. 25, 2010, pp. 27-32.
[23]J. P. Peter, “Reliability: A review of psychometric basics and recent marketing practices,” Journal of Marketing Research, Feb. 1979.
[24]吳統雄，“態度與行為研究的信度與效度：理論、應用、反省”，2018. [Online]. Available:
http://tx.liberal.ntu.edu.tw/~purplewoo/methodology/Analy-Reliability_Validity.htm
[25]Types of Reliability. The Research Methods Knowledge Base. Oct. 2006. [Online]. Available:
http://www.socialresearchmethods.net/kb/reltypes.php
[26]L. J. Cronbach and P. E. Meehl, “Construct validity in psychological tests,” Psychological Bulletin, vol. 52, pp. 281-302, July 1955
[27]TVBS News, “TVBS新聞精華”,[Online]. Available:
https://www.youtube.com/watch?v=3AxVc3cWzNM
[28]NBArtv, “Jason Williams' Streetball Moves White Chocolate”, [Online]. Available:
https://www.youtube.com/watch?v=PfLNJxlHxGU&t=134s
[29]Blender, “Big buck bunny”, [Online]. Available:
https://www.youtube.com/watch?v=aqz-KE-bpKQ
[30]SOGI, “Zenfone5Q(ZC600KL)”, [Online]. Available:
https://www.sogi.com.tw/products/asus_zenfone_5q/13775
[31]M. Seufert et al., “A survey on quality of experience of HTTP adaptive streaming,” IEEE Comm. Surveys Tut., vol. 17, no. 1, pp. 469–492, Sept. 2014.
[32]Z. Duanmu et al., “A quality-of-experience index for streaming video,” IEEE Journal on Selected Topics in Signal Processing, vol. 11, no. 1, Feb. 2017.
[33]M.-N. Garcia et al., “Quality of experience and HTTP adaptive streaming: A review of subjective studies,” Proc. IEEE International Workshop on Quality Multimedia Experience, Singapore, Sep. 18-20, 2014, pp. 141–146.
[34]Kej's FLV Retriever, [Online]. Available: http://kej.tw/flvretriever/
[35]S. Bradner and J. McQuaid, “Benchmarking methodology for network interconnect devices,” IETF RFC 2544, Mar. 1999.
[36]B. Constantine et al., “Framework for TCP throughput testing,” IETF RFC 6349, Aug. 2011.
[37]G. Almes, S. Kalidindi and M. Zekauskas, “A one-way packet loss metric for IPPM,” IETF RFC 2680, Sept. 1999.
[38]A. Morton, “Round-trip packet loss metrics,” IETF RFC 6673, Aug. 2012.
[39]G. Almes, S. Kalidindi and M. Zekauskas, “A one-way delay metric for IPPM,” IETF RFC 2679, Sept. 1999.
[40]均方根誤差RMSE的優點以及用R語言計算RMSE, [Online]. Available:
https://kknews.cc/tech/lzjlxxb.html
[41]Y. Chen, K. Wu, and Q. Zhang, “ From QoS to QoE: A tutorial on video quality assessment,” IEEE Comm. Surveys Tut., vol. 17, no. 2, pp. 1126-1165, 2015.
[42]杜千煜（2018）。OTT視訊服務體驗品質指標之探討與應用。國立高雄第一科技大學電腦與通訊工程系碩士班碩士論文