Operator-governed SON coordination in downlink LTE networks

Although future radio access networks (RAN) will be empowered by Self-Organizing Network (SON) mechanisms, operator governance and coordination remain key requirements, in order to guarantee a robust, stable and desired network operation. This paper investigates the coordination of two promising SON mechanisms, namely Inter-Cell Interference Coordination (ICIC) and Capacity and Coverage Optimization (CCO), according to the operator policies in the context of a downlink LTE network. For this purpose, the paper intends to identify a methodology that can also be generalized beyond ICIC and CCO coordination. In this direction, the interactions between the two SON mechanisms are first modelled using a concept map methodology. Then, an appropriate mathematical formulation is designed to analytically describe the SON coordination as a weighted multi-objective optimization problem. The operator weights stand for the priority that the operator gives to each SON mechanism. Simulation results are presented in order to evaluate the coordination approach. They confirm that the operator can achieve a trade-off among even conflicting objectives by adjusting the weights in accordance to business goals. Moreover, the operator can offline elaborate on the best selection of weights in order to achieve a robust, stable and desired network operation.