An Adaptive ARQ (Automatic Repeat reQuest) Strategy for Packet Switching Data Communication Networks

Automatic Repeat reQuest ARQ techniques are often used by a packet switching data communication network to provide an error-free communications link between stations. The ARQ technique ensures consistent data quality under varying link conditions. Unfortunately, the information throughput is link dependent and as the noise or interference on the link increases, the throughput decreases. In an effort to improve the throughput on a short range, RF, packet switching data communications network, an adaptive ARQ strategy applied to Stop- and-Wait SW protocols was developed. To provide a system designer with flexibility, different adaptive strategies for different system and link conditions were developed. Examples of information transfer between two stations using the adaptive SW protocol are presented. A simulation to compute the throughput efficiency of several adaptive SW protocols was performed. A comparison of the throughput efficiencies of the simulated adaptive SW protocol with the non-adaptive SW protocol showed good gains could be achieved using the adaptive strategy when the networks are subject to high channel bit error rates. Theses.