植基於QoE之網路電話系統語音品質監測機制之研究

A Study on QoE-based Speech Quality Monitoring Mechanism for VoIP System

 

陳建誠

國防大學管理學院碩士

海軍司令部業參

台北市中山區北安路305

 

劉興華

國立交通大學資管博士

聲威網際科技公司總經理

新北市中和區中正路73610樓之9

 

傅振華*

國立交通大學資管博士

國防大學資管系副教授

台北市北投區中央北路二段70

 

 

摘要

在大型組織機構中佈署網路電話系統時,雖然使用者可透過網路流量控管語音封包的QoS(Quality of Service)或是啟動MPLS(Multi-Protocol Label Switching)來確保語音的品質;然而,在實務上,網路電話語音品質仍需要依靠即時監控系統來達到有效的量測結果,讓大型組織的網管人員得以建置一個完整的網路電話管理系統。本研究植基於改良簡易式E模型中的QoE(Quality of Experience)演算法,建置一個網路電話系統架構上量測語音品質QoE的雛型系統,提供管理者有效且即時監控網路電話服務通話品質的量測工具;透過此一雛型系統,網路電話管理者可以省略複雜的主動式音頻評估方式,即可及時獲得端點對端點的用戶通話數據,精量測語音品質的平均意見得分(Mean Opinion Scores, MOS)。本研究依據網路電話常見可能的通信環境,提出5種實作想定,藉以瞭解研究所建置語音品質量測QoE雛型系統的可行性與實用性,經各想定的測試後,本研究發現:在不同網路電話系統架構下的語音品質量測,研究所建置的語音品質量測QoE雛型系統均能即時且精評量用戶的網路電話通話品質,同時在經由語音品質告警門檻的建立,將使管理者更能確實掌握大型網路電話系統的運作效能。

關鍵詞:網路電話、QoE、語音監控、改良簡易式E模型

 

Abstract

In general, users can control the voice QoS with shaping network traffic or initiate MPLS to ensure voice quality when they deploy a VoIP system in a large organization. However, in practice, voice quality of VoIP still relies on a real-time monitoring system to achieve effective measurement results, it allows network administrators of large organizations to build a complete VoIP management system. Based on the Improved Simplified E-model, this study implements a prototype system to measure voice quality QoE on the VoIP system architecture. The implemented prototype system provides a useful measurement tool for administrators to monitor real-time VoIP traffic over a network effectively. With this system, VoIP administrators can obtain users’ end-to-end call data instantly without a complex active audio evaluation method and measure the voice quality, MOS (Mean Opinion Scores), accurately. Based on several common communication environment of Internet telephony, this study proposed five practical scenarios to understand the feasibility and practicability of the implemented QoE prototype system for VoIP quality measurement. This study based on the 5 scenarios to receive several test results and found out the QoE prototype system can measure the quality of VoIP calls of users instantly and accurately under different VoIP system architectures. Meanwhile, with a threshold of VoIP quality setting, VoIP administrators can handle better operational effectiveness for a large-scale VoIP system.

Keywords: VoIPQoESpeech monitoringImproved Simplified E-mode