Generalized Predictive Control of the Time Window for Energy Efficient Ethernet With Prediction

Abstract

The strategy of determining the occasion to enter and leave the Low Power Idle (LPI) state is crucial to the power savings and incurred queuing delays of the Energy Efficient Ethernet. The novel strategy EEEP (Energy Efficient Ethernet with Prediction) proposed recently achieves good energy-saving and limited latency by allocating the LPI duration within a fixed time window. In this letter, we observe that the average incurred delays increase linearly while the energy consumption ratio curve is hyperbolic with the increase of the time window parameter. Accordingly, when the performance is quantified by the cost defined as a linear combination of power consumption ratio and average queuing delay, an optimal time window parameter would minimize the cost. Furthermore, we propose the GPC-EEEP strategy, which automatically adjusts the time window parameter of EEEP to the optimal value with the generalized predictive control method. Simulations driven by both synthetic traffic and real traces confirm that GPC-EEEP significantly improves the cost by automatically settling the time window parameter according to dynamic traffic.