Dormant Cells and Idle Modes

This chapter presents a framework that is used to quantify the energy saving gains of deploying small cells using a parametric model. Moreover, it presents a few solutions to reduce the energy consumption of small cell base stations (BSs) by effectively enabling idle mode procedures for such BSs. In the chapter, the potential energy saving gains of deploying small cells are quantified by using a parametric power consumption model. With the expected wide-spread deployments of small cells, the power efficiency of these cells in idle mode becomes an important aspect. And also from the performance and interference perspective, muting the small cell BSs when they are not serving a user equipment (UE) is beneficial. A centralized idle mode procedure can address many of the shortcomings of the decentralized approach. In this scheme, small cell BSs can enter deep sleep modes and a centralized entity is responsible for waking them up, when it is necessary.