An adaptive ARQ strategy for packet switching data communication networks

Abstract

Automalic Repeat reQuest (ARQ) techniques are often used by a packet switching data communication network to provide an error-free communications link between stations. The A RQ 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.