Perceptual Optimization of Playout Buffer in VoIP applications

• Main Authors: Wu Chun-Feng, 吳俊鋒
• Other Authors: Chang Wen-Whei
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/68194251214397397219

碩士 === 國立交通大學 === 電信工程系所 === 94 === Packet delay and loss are two essential problems to real-time voice transmission over IP networks. In the proposed system, the playout delay is adaptively adjusted based on a simplified version of the conversational-quality E-model. In this thesis, a perceptually motivated optimization criterion and a practically feasible new algorithm are stated for adaptive playout buffer design. This new buffer design is formulated as an unconstrained optimization problem leading to a better balance between end-to-end delay and packet loss and it can be used in conjunction with per-talkspurt as well as per-packet delay adjustment. We compared the perceived speech quality using the E-model methodology for adaptive playout algorithms with fixed and dynamic setting of the safety factor. Experimental results show that the proposed playout buffer algorithm can achieve the optimum perceived speech quality under various network conditions.