Subjective Quality Assessment of One-to-One Video-Telephony Services

Video-telephony applications have been widely used in people's daily life, such as online conferences, online education, and socialization. Especially during the COVID-19 pandemic, the business volume of video-telephony services has generally increased rapidly. This leads to a growing need for video-telephony service quality assessment and monitoring. This paper presents the subjective tests conducted in 'Computational model used as a QoE/QoS monitor to assess video-telephony services' (G.CMVTQS) project, which is under study in ITU-T SG12 Q.15. Two types of subjective tests are designed. Audiovisual material subjective test focuses on the quality of multimedia streams, while conversational subjective test focuses on the quality of interaction experience. These tests simulate real-life situations in video-telephony with different types of user terminals (PCs, TVs and mobile phones), environments (office, home, restaurant and outdoor), audio/video parameters (resolution, frame rate, bit rate and codec) and network impairments (packet loss, delay, jitter, bandwidth, synchronization). The final subjective database built collaboratively by five laboratories in different countries will be analyzed in the near future and provide more insights to develop new QoE/QoS monitor models for video-telephony.