Adaptive error control for slowly varying channels

Presents an adaptive error control technique based on the use of type-I hybrid-ARQ protocols. The communication channel is assumed to be slowly varying and is modeled using a finite state Markov chain. The system counts the number of retransmission requests during an observation interval called a frame and, together with knowledge of the error control strategy in use and a set of thresholds, estimates the state of the channel. The coding strategy which maximizes throughput while maintaining a minimum required level of reliability is chosen for use in the next frame. Examples are provided showing system design and performance using families of Reed-Solomon codes.<>