In almost all conventional transport protocols, ARQs (automaticrepeat request) have been used to recover lost packets, in whichreceivers would request sources to retransmit lost packets. In theseretransmission based error recovery schemes, the transmission delay canreach an unacceptable level for traffic with stringent delay constraintsin high speed networks because their propagation delay is very largerelative to packet transmission times. On the other hand, FEC (forwarderror correction) adds redundant packets to data ones, all of which areorganized into a group called a block, and hence allows the receivers tocorrect some of the lost packets without retransmissions. Thiscapability is desirable for high speed networks. The authors exactlyanalyze the distribution of the number of cells lost within a block inATM networks with correlated cell arrivals, and examine the benefits dueto FEC by means of the analysis
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