A simulation study of two-level forward error correction for lost packet recovery in B-ISDN/ATM

The major source of errors in broadband integrated services digital network/asynchronous transfer mode (B-ISDN/ATM) systems is expected to be buffer overflow during congested conditions, resulting in lost packets. The performance of the end-to-end system can be made much less sensitive to cell loss by means of forward error correction. The results of a simulation study for an ATM network where forward error correction is performed at both the cell level and the PDU level are presented. The results indicate that cell losses are highly correlated in time, and analytical models ignoring this fact will not yield accurate results; the correlation of cell losses is similar to burst errors in digital communication, and similar code interleaving techniques should be used; and coding cells and PDUs separately provide this interleaving effect, and this joint code outperforms coding only at the cell level or only at the PDU level in almost all cases simulated.