Two-Tier 360-Degree Video Delivery Control in Multiuser Immersive Communications Systems

In the immersive communications systems, video information is stringently delivered for extended reality applications. Since users may demand various immersive experience and have different levels of view prediction accuracy, the two-tier 360-degree video delivery frame structure with dynamic transmission time interval duration needs to be designed appropriately. To maximize the system's quality of experience, two new frame structures and power control are proposed. Meanwhile, the synchronous and asynchronous cases with different computational complexities are addressed. The results demonstrate the effectiveness of the proposed design and indicate that flexible frame structure is beneficial for multiuser immersive communications.acceptedVersionPeer reviewe

View-popularity-driven joint source and channel coding of view and rate scalable multi-view video

We study the scenario of multicasting multi-view video content, recorded in the video plus depth format, to a collection of heterogeneous clients featuring Internet access links of diverse packet loss and transmission bandwidth values. We design a popularity-aware joint source-channel coding optimization framework that allocates source and channel coding rates to the captured content, such that the aggregate video quality of the reconstructed content across the client population is maximized, for the given packet loss and bandwidth characteristics of the clients and their view selection preferences. The source coding component of our framework features a procedure for generating a view and rate embedded bitstream that is optimally decodable at multiple data rates and accounts for the different popularity of diverse video perspectives of the scene of interest, among the clients. The channel coding component of our framework comprises an expanding-window rateless coding procedure that optimally allocates parity protection bits to the source encoded layers, in order to address packet loss across the unreliable client access links. We develop an optimization method that jointly computes the source and channel coding decisions of our framework, and also design a fast local-search-based solution that exhibits a negligible performance loss relative to the full optimization. We carry out comprehensive simulation experiments and demonstrate significant performance gains over competitive stateof- the-art methods (based on H.264/AVC and network coding, and H.264/SVC and our own channel coding procedure), across different scenario settings and parameter values