Multi-criteria decision for small cell switch off in ultra-dense LTE networks

The concept of a densely deployed heterogeneous network is one of the main approaches of modern wireless networking research to satisfy the growth of the traffic demand. However, such trend leads to a significant network energy consumption increment. One of the effective techniques to save energy is to switch off some underutilized cells during off peak hours. In this line, the focus of this paper is to decide the number of base stations to switch off in order to maximize the energy saving, while maintaining coverage, capacity and Quality of Service. We use a combination of Grey Relational Analysis and Analytic Hierarchy Process tools to trigger the switch off actions, jointly considering multiple decision inputs for each cell. The co-tier interference, typical of small cell networks, is also considered in the decision making by introducing a graph - based technique for dynamic resource allocation.