Therdpong Daengsi

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This paper presents new evidence about user perception of VoIP quality that is inconsistent with the general understanding of three codecs know as G.729, G.711 and G.722. The focus of the study is aimed at VoIP quality evaluation by Thai users that use the Thai language which is tonal. This study was conducted by using conversation-opinion tests. The(More)
This paper presents a preliminary study of quality of experience (QoE) of VoIP that are provided as social network services using Perceptual Evaluation of Speech Quality (PESQ) with Thai and Chinese speech samples. This study focuses on VoIP quality of the free call feature from Facebook and LINE, which are the popular social network site and the popular(More)
To aid authenticity, accuracy and reliability of subjective measurement of VoIP quality measurements, this paper proposes a model that has been created from the subjective MOS, instead of using existing objective measurement methods for VoIP quality measurement. The proposed model of VoIP quality measurement method is based-on Thai users. The data has been(More)
This paper presents a study of VoIP - Quality of Experience (VoIP-QoE) of a well-known VoIP application and three modern ones, Skype, LINE, Tango and Viber, using Perceptual Evaluation of Speech Quality (PESQ) with English speech samples. From this study, it has been found that Skype and LINE tend to provide better VoIP quality than Tango and Viber,(More)
This paper presents an enhanced objective method for VoIP quality evaluation. However, instead of improving the original E-model for G.729, the Simplified E-model has been enhanced using subjective MOS estimation model based-on Thai users, who used Thai-tonal language. The different results from Simplified E-model and subjective MOS estimation model have(More)
The E-model is a non-intrusive measurement method that many researchers have applied to the study of VoIP quality measurement. While the Simplified E-model is a modified version from the original, it can still be used as an alternative solution. Nevertheless, it has been found that the E-model and the Simplified E-model still require further improvement.(More)
This paper briefly presents the study of VoIP quality from two popular social network applications over 3G and 4G in Bangkok, covering both stationary and mobility. It has been found that, based-on stationary tests, 4G does not provide better VoIP quality than 3G, although the downlink speed of 4G is faster that 3G by about 5-7 times. However, based on(More)
Based on Quality-of-Experience (QoE), this paper presents a comparison of video telephony quality of two applications, LINE and Tango, using Peak Signal to Noise Ratio (PSNR) measurements over the 3G mobile networks. The PSNR values have been obtained using the video processing application, called the MSU video quality measurement tool. Then, the PSNR(More)