Models are developed to analyze the throughput of ARQ protocols, such as Go Back N and Selective Repeat, and protocols without ARQ. Forward error correction is added to these models to study the interactions between these mechanisms.
In systems where sending FEC has a negligible effect on the channel loss probability, the goodput of streams increases. Reducing the data throughput and including error correction packets, thus keeping the data rate perceived by the channel constant, has advantages in the Go Back N protocol when the channel loss rate is above a certain range. Furthermore, these models form a starting point with which to study more complicated models such as the TCP.