A conflict avoidance scheme between mobility load balancing and mobility robustness optimization in self-organizing networks

In the self-organizing networks, mobility load balancing (MLB) and mobility robustness optimization are two significant functions. There is a close relationship between them, as they both adjust the handover parameters to achieve their respective goals. The conflict may happen when both of them adjust the same handover parameters in the opposite directions. Conflict avoidance methods have been proposed in the existing literature. However, all of the existing methods cannot get the optimum values of handover parameters. Moreover, the load distribution of the neighbor cells is neglected, which has a great impact on the network performance. To address these issues, an effective scheme based on the load level of neighbor cells is presented. Firstly, the objectives for MLB are designed and the MLB problem is formulated as a linear programming problem, which can be readily solved by the well-established methods. Furthermore, considering the load distribution of the neighbor cells, the appropriate values of handover parameters for MLB can be obtained. Finally, we provide the framework of MLB procedures. The simulation results verify the performance of the proposed scheme outperforms the exiting methods.