Throughput Comparison of Automatic Repeat Request Assisted Butterfly Networks

The maximum achievable throughput and the steady-state throughput of the Butterfly networks are investigated and compared in the context of three types of automatic repeat request (ARQ) schemes of, namely, the stop-and-wait ARQ (SW-ARQ), go-back-$N$ ARQ (GBN-ARQ) and the selective-repeat ARQ (SR-ARQ). Our studies show that, at a given packet error rate (PER), the SW-ARQ scheme yields the lowest throughput while the SR-ARQ scheme can attain the highest throughput, among the three ARQ schemes considered. At a very low PER, the GBN-ARQ may achieve a similar throughput as the SR-ARQ. However, as the PER increases, the throughput achieved by the GBN-ARQ converges to that of the SW-ARQ.