An enhanced MRO method for smart antenna capable (H)eNBs in LTE networks

A self-optimization function called mobility robustness optimization (MRO) is to gradually find-tune the handover configuration parameters by analyzing handover history. It is expected that the smart antenna can help the MRO function to further decrease the number of radio link failures. However, current MRO function does not take smart antenna into consideration. This paper proposes an enhanced MRO method which supports base stations with smart antennas. This method proposes the idea of beam pattern pair which is a pair of source beam angle and target beam angle. A beam pattern pair classification method is also proposed which utilizes the historical statistics of handovers to fine-tune the handover configuration parameters each for a group of beam pattern pairs so as to reduce the radio link failures. Simulation results show that the proposed beam-pattern based MRO method is 7% lower than the normal MRO method with respect to the radio link failure rate.