As wireless technology continues its rapid evolution, the sixth-generation (6G) networks are capable of offering exceptionally high data transmission rates as well as low latency, which is promisingly able to meet the high-demand needs for digital twins (DTs). Quality-of-experience (QoE) in this situation, which refers to the users’ overall satisfaction and perception of the provided DT service in 6G networks, is significant to optimize the service and help improve the users’ experience. Despite progress in developing theories and systems for digital twin transmission under 6G networks, the assessment of QoE for users falls behind. To address this gap, our paper introduces the first QoE evaluation database for human digital twins (HDTs) in 6G network environments, aiming to systematically analyze and quantify the related quality factors. We utilize a mmWave network model for channel capacity simulation and employ high-quality digital humans as source models, which are further animated, encoded, and distorted for final QoE evaluation. Subjective quality ratings are collected from a well-controlled subjective experiment for the 400 generated HDT sequences. Additionally, we propose a novel QoE evaluation metric that considers both quality-of-service (QoS) and content-quality features. Experimental results indicate that our model outperforms existing state-of-the-art QoE evaluation models and other competitive quality assessment models, thus making significant contributions to the domain of 6G network applications for HDTs.
{"title":"Quality-of-Experience Evaluation for Digital Twins in 6G Network Environments","authors":"Zicheng Zhang;Yingjie Zhou;Long Teng;Wei Sun;Chunyi Li;Xiongkuo Min;Xiao-Ping Zhang;Guangtao Zhai","doi":"10.1109/TBC.2023.3345656","DOIUrl":"10.1109/TBC.2023.3345656","url":null,"abstract":"As wireless technology continues its rapid evolution, the sixth-generation (6G) networks are capable of offering exceptionally high data transmission rates as well as low latency, which is promisingly able to meet the high-demand needs for digital twins (DTs). Quality-of-experience (QoE) in this situation, which refers to the users’ overall satisfaction and perception of the provided DT service in 6G networks, is significant to optimize the service and help improve the users’ experience. Despite progress in developing theories and systems for digital twin transmission under 6G networks, the assessment of QoE for users falls behind. To address this gap, our paper introduces the first QoE evaluation database for human digital twins (HDTs) in 6G network environments, aiming to systematically analyze and quantify the related quality factors. We utilize a mmWave network model for channel capacity simulation and employ high-quality digital humans as source models, which are further animated, encoded, and distorted for final QoE evaluation. Subjective quality ratings are collected from a well-controlled subjective experiment for the 400 generated HDT sequences. Additionally, we propose a novel QoE evaluation metric that considers both quality-of-service (QoS) and content-quality features. Experimental results indicate that our model outperforms existing state-of-the-art QoE evaluation models and other competitive quality assessment models, thus making significant contributions to the domain of 6G network applications for HDTs.","PeriodicalId":13159,"journal":{"name":"IEEE Transactions on Broadcasting","volume":"70 3","pages":"995-1007"},"PeriodicalIF":3.2,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139947547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-01-03DOI: 10.1109/TBC.2023.3342707
Zongyao Hu;Lixiong Liu;Qingbing Sang
Spherical signals of omnidirectional videos need to be projected to a 2D plane for transmission or storage. The projection will produce geometrical deformation that affects the feature representation of Convolutional Neural Networks (CNN) on the perception of omnidirectional videos. Currently developed omnidirectional video quality assessment (OVQA) methods leverage viewport images or spherical CNN to circumvent the geometrical deformation. However, the viewport-based methods neglect the interaction between viewport images while there lacks sufficient pre-training samples for taking spherical CNN as an efficient backbone in OVQA model. In this paper, we alleviate the influence of geometrical deformation from a causal perspective. A structural causal model is adopted to analyze the implicit reason for the disturbance of geometrical deformation on quality representation and we find the latitude factor confounds the feature representation and distorted contents. Based on this evidence, we propose a Causal Intervention-based Quality prediction Network (CIQNet) to alleviate the causal effect of the confounder. The resulting framework first segments the video content into sub-areas and trains feature encoders to obtain latitude-invariant representation for removing the relationship between the latitude and feature representation. Then the features of each sub-area are aggregated by estimated weights in a backdoor adjustment module to remove the relationship between the latitude and video contents. Finally, the temporal dependencies of aggregated features are modeled to implement the quality prediction. We evaluate the performance of CIQNet on three publicly available OVQA databases. The experimental results show CIQNet achieves competitive performance against state-of-art methods. The source code of CIQNet is available at: https://github.com/Aca4peop/CIQNet