Layered Encoding and Transmission of Video in Heterogeneous Environments

Applications of real-time video transmission in heterogeneous network and computing environments, like the Internet, need to be highly scalable and adaptive in terms of bandwidth and processing requirements. Layered video coding in combination with layered transmission schemes have been proposed as a solution to network and terminal equipment heterogeneity. In this paper we identify the fundamental requirements of layered video coding and transmission architectures, and review the different types of layering mechanisms available. Two applications are emphasized: multipoint videoconferencing and point-to-point video streaming. The implications of layer granularity for network bandwidth utilization are experimentally investigated through simulations.