Adaptive polling schemes for an ATM bus

The authors consider a high-speed ATM (asynchronous transfer mode) bus, which can serve a small number of stations (⩽16). The bus is slotted and each slot is long enough to contain one ATM cell. Transmission on the bus is controlled by an arbitrator. Each station sends it status information to the arbitrator at regular intervals. Based on this information the arbitrator makes polling decisions. Due to transmission and processing delays the arbitrator makes decisions based on status information which is a few bus slots old. Adaptive polling assuming bursty arrivals is proposed. The schemes take into account both the cell loss probability and the mean waiting times. The polling policies focus on equalizing the mean waiting time (delay) in the buffers before a cell gets transmitted on the bus. The advantage of these schemes over ordinary polling is demonstrated