Flow-Level-Delay Constraint Small Cell Sleeping with Macro Base Station Cooperation for Energy Saving in HetNet

In this paper, we consider the delay tolerable data traffic transmission in Heterogeneous Networks (HetNet) and propose a flow-level-delay constraint small cell sleeping scheme to achieve energy saving gain. We use the flow-level model to capture the process of data transmission in micro base station (BS) which is the small cell we consider. Our scheme takes advantage of the feature of HetNet and designs macro BS cooperation in the process of dynamic micro BS sleeping, which helps achieve more energy saving. Through the Markov state transfer diagram and solving the balance equation, we get the numeric performance of power consumption and delay in our scheme. Then we solve a cost function minimization problem to get the optimal energy-delay tradeoff curve which helps to get the sleep scheme parameter settings. Our work cast light on how the energy consumption and delay performance is affected by dynamic sleep control and HetNet environment. And finally simulation shows that our proposed scheme can achieve better energy saving.