Reducing Power Consumption by Joint Sleeping Strategy and Power Control in Delay-Aware C-RAN

Focus on the energy saving problem in cloud radio access network (C-RAN), this paper jointly optimizes the system power consumption and delay performance with the consideration of quality-of-service (QoS) and fronthaul capacity. First, to make the power consumption model compatible with C-RAN, we give a modified power consumption model of base station (BS) on the basis of the well-known EARTH model. Then, to save the system power consumption, the sleeping strategy is introduced to dynamically switch ON/OFF the BS. In order to analyze BS mode under the sleeping strategy, the arriving users are modeled as a discrete-time queuing network. Based on the global balance equations of the queuing network, the probability that the BS is in active mode can be obtained. In the light of the above result, to further reduce the system power consumption, power control is introduced under the constraint of QoS and fronthaul capacity. Meanwhile, by applying Lyapunov method, a different way to consider the delay performance is provided, and at the same time, network stability is guaranteed. Simulation results show that the proposed algorithm can balance the power consumption and delay by adjusting relevant parameters, and achieve the goal of energy saving on the basis of delay control.