摘要
IP电话作为一种新型的电信业务 ,具有很大的发展潜力 .但也存在一个致命的弱点 ,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 ;预取技术和速率调节技术等 .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 。
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.
出处
《小型微型计算机系统》
EI
CSCD
北大核心
2000年第8期875-877,共3页
Journal of Chinese Computer Systems
基金
国家自然科学基金!(批准号 69773 0 46)