This paper presents an investigation of issues related to the support of Realtime compressed digital video on shared access packet transmission systems. Packet transport mechanisms are motivated for compressed digital video because of their inherent ability to average data from many bursty variable rate sources, potentially eliminating the need for buffer controlled adaptation of the video coding algorithm. The feasibility of employing conventional link- and transport-level protocol services to transmit compressed video is examined by focusing on two specific practically important scenarios for compressed video transmission: 1) multipoint-to-multipoint video transmission using a 200 Mbit/s implicit token passing (ITP) Fiberoptic LAN and 2) point-to-multipoint broadcast video distribution using a 90 Mbit/s packet-TDM direct-broadcast satellite channel. In order to evaluate the performance of such shared access broadband packet video systems, we develop accurate simulation models, driven by realistic “broadcast quality” AST-DPCM compressed video sources, for the example ITP-LAN and packet-TDM systems. The models are used to determine design tradeoffs between channel throughput, video quality (measured by clipping probability), and the transport-level and media-access-level protocol features and parameters implemented in the packet video network interface unit (NIU).
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering