While a mobile device is connected to the network, it measures the signal strength of neighbouring cells. Based on the device’s reports, the eNodeB can take the decision of performing a handover, which consists of handing over the connection to a neighbour cell with a better signal. > Handover procedure prevents the connection from dropping and improves the data throughput. ### Mobility Robustness Optimisation use case focuses on improving the handover process. - **RAT = Radio Access Technologies** - **LTE = Long Term Evolution** - **Connection failure due to intra-LTE or inter-RAT mobility:** - The connection failure can be due a too early HO, due to a too late HO or due to a HO to a wrong cell. - **Unnecessary HO to another RAT (too early IRAT HO with no radio link failure):** - It can happen that the UE is handed over from E-UTRAN to another RAT (eg. UTRAN or GERAN) even though the coverage was sufficient for the service. Therefore, the handover may be considered unnecessary. - **Inter-RAT ping-pong:** - An UE can perform a handover from a cell in a source RAT to another cell with a different RAT, then, after a limited amount of time, the UE is handed back to the source cell again. This event may happen more than one time. The parameters that can be optimised by the MRO functionality are the time to trigger, hysteresis, cell individual offset, frequency-specific offset and cell re-selection parameters #telco