A Fluid model based Heuristic for Optimal Speed-scaling of Multi-class Single Server Queues

Abstract

We investigate the energy-delay tradeoff in multi-class queues in which the server can regulate its speed according to the load of the system. Assuming that the queue is initially congested, we investigate the rate allocation to the classes that drains out the queue with minimum total energy and delay cost. We propose to solve this stochastic problem using a deterministic fluid approximation. We show that the optimal-fluid solution follows the well-known c? rule and obtain an explicit expression for the optimal speed. Numerical results show the utility and the applicability of the fluid-optimal policy.