Loss-resilient ATM protocol architecture for MPEG-2 video communications

MPEG-2 video communications over ATM networks is one of the most active res earch areas in the field of computer communications. In the transmission pr ocess of a variable bit rate video signal over an ATM network, cells are in evitably exposed to delays, errors, and losses due to the statistical multi plexing used in these networks. These phenomena affect the quality of the v ideo signal, and without adequate measures to control the propagation of th e impairments, the quality of the service may fall below acceptable levels, In this paper, we study the impact of cell losses on the quality of an MPE G-2 video sequence encoded in a variable bit rate mode. We introduce a set of control mechanisms at different levels of the protocol architecture to b e used in MPEG-2-based video communications systems using ATM networks as t heir underlying transmission mechanism. Our results (using different video sequences) show the effectiveness to improve the video quality by using a s tructured set of control mechanisms to overcome for the loss of cells carry ing VBR MPEG-2 video streams. We argue that in order to be able to create v ideo systems able to cope with cell losses encountered in computer communic ations systems, a structured set of error-resilient protocol mechanisms is needed.