关键词: 服务质量映射, 网络语音, 感知语音质量评估, 自组织映射神经网络模型, 扩展自组织神经网络模型

Abstract: The Quality of Service（QoS） of VoIP depends on several factors such as throughput，end-to-end delay，dithering，and packet loss rate.The Perceptual Evaluation of Speech Quality（PESQ） is difficult to categorize the quality of VoIP rightly under the real network environments.To totally take account of the effects of several QoS-related parameters，this paper proposes an expanded self-organizing neural network，which can map high-dimensional data into simple geometric relationships on a low-dimensional display effectively.The impact of end-to-end delay，packet loss，network jitter，audio codec，QoS-related parameters and system identifiers are used as inputs to an ESOM model to predict speech quality directly after giving some training，which also can efficiently evaluate the positioning of QoS level for each condition composed of several variables at real-time.

Key words: QoS map, voice over IP, PESQ, self-organizing map, expanding SOM