Delay minimization of the adaptive go-back-N ARQ protocols for point-to-multipoint communication

Some data-link layer error control go-back-N ARQ (automatic repeat-request) protocols are studied that are suitable for point-to-multipoint communication over broadcast channels where data are delivered to the destinations in the order they are sent. A series of protocols differing in the way that the sender uses the outcomes of the previous transmissions are studied. The system delay, rather than the throughput, is the optimization measure. The optimal number of copies that the sender should transmit to minimize the time between when the sender first transmits a data frame and when the data frame is accepted by all the receivers is determined. The results show that sending the optimum number of copies of a data frame instead of just a single copy significantly improved the delay performance.<>