Forward error correction in ATM networks: an analysis of cell loss distribution in a block

In almost all conventional transport protocols, ARQs (automatic repeat request) have been used to recover lost packets, in which receivers would request sources to retransmit lost packets. In these retransmission based error recovery schemes, the transmission delay can reach an unacceptable level for traffic with stringent delay constraints in high speed networks because their propagation delay is very large relative to packet transmission times. On the other hand, FEC (forward error correction) adds redundant packets to data ones, all of which are organized into a group called a block, and hence allows the receivers to correct some of the lost packets without retransmissions. This capability is desirable for high speed networks. The authors exactly analyze the distribution of the number of cells lost within a block in ATM networks with correlated cell arrivals, and examine the benefits due to FEC by means of the analysis