Bandwidth allocation for isochronous connections in DQDB using the PA scheme

The PA scheme in DQDB is suitable for constant-rate and connection-oriented transmissions. In this paper, we propose and evaluate four bandwidth allocation policies, which are based on the harmonic case of the pinwheel scheduling algorithm^{1, 2} for isochronous connections using the PA scheme. The idea is to classify isochronous connections into several harmonic classes according to their periods. Isochronous connections from the same class can share the same unit channel as long as the total bandwidth is no greater than the available bandwidth they requested in the unit channel. The main advantage of our schemes is that all isochronous connections can be established with zero variability. The proposed policies are evaluated in terms of their blocking probabilities and processing overhead via both simulation and analysis.