An improved selective-repeat ARQ strategy

ARQ is the term used for an automatic system which provides error correction by utilizing a constant ratio code and a closed loop to request retransmission of mutilated characters. A selective repeat strategy was described by Stuart (1963). In a selective-repeat ARQ system, blocks are numbered and ACKed (acknowledged) or NACKed by number. Practical selective-repeat ARQ procedures fall far short of channel capacity when the error probability is high. The present investigation is concerned with a new selective-repeat ARQ strategy, which is shown to be superior, with respect to its throughput, to earlier techniques.