Stop-and-selective repeat ARQ scheme for a high-speed transport protocol

Research into a transport protocol for high-speed networks is one of the most progressive areas in the field of computer communications. In high-speed networks using optical fiber as a transmission medium that gives the bandwidth from a hundred Mbits/s to Gbits/s, the roundtrip (propagation) delay and bandwidth product becomes large. It is well known that for an increase in this product, the throughput performance of the conventional error control procedures such as the go-back-N-based-ARQ scheme does degrade significantly. Therefore, a new protocol based on a selective-repeat ARQ scheme must be developed. The authors propose the stop-and-selective repeat (SSR) ARQ protocol and analyze the throughput performance of it. The throughput formula is exactly derived in terms of the roundtrip delay, the frame error rate, and the window size of from one to two roundtrip delays. The window size needed to offer the adequate throughput greater than 95% is shown.