Towards Self-Organizing Mobility Robustness Optimization in Inter-RAT Scenario

The deployment of Long Term Evolution (LTE) system will be at first concentrated on areas with high user traffic overlaying with legacy second (2G) or third generation (3G) mobile system. Consequently, the limited LTE coverage will result in many inter-radio access technology (RAT) handovers from LTE to 2G/3G and vice versa. Trouble-free operation of inter-RAT handovers is very important for mobile operators. However, the joint parameter optimization of different RATs is complex and difficult with traditional optimization means. Thus, an autonomous inter-RAT mobility robustness optimization (MRO) is required. In this work, inter-RAT mobility problems and related inter-RAT key performance indicators (KPIs) are identified. Based on simulative investigations, the impact of the mobility parameters on KPIs is analyzed. Results show that the performance of the network highly depends on the configuration of the mobility parameters and there is a potential for developing a self-organizing inter-RAT MRO algorithm.