In this paper we consider the problem of designing a good ARQ protocol for a message transmission environment characterized by high error rates and/or long propagation delays. We derive the average queue length for an idealized ARQ protocol for such an environment. We also describe a modification that can be made to existing ARQ protocols which can significantly decrease queue lengths in such an environment. We show that for the case of low message traffic rates, the modified Go Back-

protocol approaches the idealized scheme in performance.