Automatic Veri cation of Asynchronous Retransmission Go-Back-N ARQ Protocols Using the Concurrency Workbench

The Go-Back-N and Selective-Repeat automatic repeat request (ARQ) protocols are widely used for error control in computer-communication networks. They are nearly optimal for channels characterized by low error rates and small propagation delays, and thus suitable for many classical data transmission applications. However, these protocols are not eecient for modern non-conventional channels with high error rates and/or large propagation delays, such as mobile links and satellite links. In this paper we present a family of new protocols, termed Asynchronous Retransmission Go-Back-N ARQ protocols, which ooer the potential for better performance in environments characterized by high error rates and/or large propagation delays. We verify that these protocols are deadlock free using the Concurrency Workbench. We also verify that all these new protocols provide the same services to applications as the basic Go-Back-N protocol, and all of them are equivalent to the basic Go-Back-N protocol from the application point view.