On the potential of FEC algorithms in building fault-tolerant distributed applications to support high QoS video communications
Bernd E. Wolfinger · 1997
Studies for distributed applications have demonstrated that application quality in distributed computing is strongly dependent on the quality of the underlyingcommunicationsystem.Besidea perform- ance characteristics the reliability properties of a communication system are playing a predominant role with regard to the qurdky achievable from applications' point of view.In this paper we study distributed applications with video communication via 10SSYcommunication systems.We develop analytical models reflecting transmission of MPEG coded video streams both without and with forward error correction (FEC).These models allow us to determine the optimum amount of redundancyto be used for PEC when communicating via constant bit rate connections.We conclude that FEC algorithms offer the potentiat for high qrsalityof-service even in the case of using a communication system with low quality. 1.MotivationA lot of earlier studim for distributed applications have demonstrated that application quality in distributed computing (as in parallel computing) is strongly dependent on the quality of the underlying communication system or communication network that is used for data exchange between application processes.Besides performance characteristics (such as throughput or transmission delays) the reliability properties of a communication system (such as probability of losing or corrupting data during transmission) are playing a predominant role with regard to the quality achievable when realizing a distributed application.In distributed computations, in particular, performance typically represents the prime quaJity criterion whereas in dktributed applications with real-time requirements (such as real-time audio/video communication) reliability of the underlying 1)~s-h at lntmation~computer Science Institute (ICSI).