OPTIMAL-CONTROL OF ARRIVALS TO TOKEN RING NETWORKS WITH EXHAUSTIVE SERVICE DISCIPLINE

The optimal control of arrivals to a two-station token ring network is analyzed in this paper. By adopting a maximum system throughput under a system time-delay constraint optimality criterion, we study a netwo rk optimality problem with the assumption that both stations have glob al information (i.e., the number of packers at each station). The cont rolled arrivals are assumed to be state-dependent Poisson streams and have exponentially distributed service time. The optimality problem wi ll be formulated using dynamic programming with a convex cost function . Combining with duality theory, we then show that the optimal control is almost bang bang and in the special case when both queues have the same service rate and sufficiently large buffers, the optimal control is further shown to be switchover. A nonlinear program is used to num erically determine the optimal local control for the purpose of compar ison. The results obtained under global and local information can be u sed to provide a measure of the tradeoff between maximum throughput ef ficiency and protocol complexity. Numerical examples illustrating the theoretical results are also provided.