提高IP电话音质的相关技术及其参数的计算

ＩＰ电话作为一种新型的电信业务,具有很大的发展潜力,但也存在一个致命弱点,即语音质量问题,本文在分析影响ＩＰ电话音质因素的基础上,提出了如何通过改进ＩＰ电话网关结构来改善ＩＰ电话音质的有关技术,如：缓冲技术等。并借鉴多媒体同步与表现的有关理论,建立了ＩＰ电话网关中缓冲区设置数目和预取语音包数目的计算模型,文章最后给出了一个实例,验证该计算模型的正确性。

SOME TECHNIQUES TO IMPROVE QoS OF IP TELEPHONY AND ITS MATHEMATICAL RELATIONSHIP

IP telephony is new service of telecommunication, it has a potential development. How to improve the quality of speech of IP telephony is a significant technique problem unsolved now. The paper analyzes the reasons degrading the voice quality and studies some techniques and methods to improve voice quality, such as buffer technique, pre storage technique, dynamic adjustment of the voice codeing rate according to the state of network, and etc. According to the theory of multimedia synchronization and present, some key parameters and mathematical relationship of QoSs, such as maximum number of buffers, and minimum number of pre storage voice packets, are analyzed. Finally, an example is used to verify the correctness of the analysis of mathematical relationship above in the paper.