The document discusses LTE mobility optimization. It describes the two principal parts of LTE mobility: RRC_Idle mode where UEs perform cell reselection, and RRC_Connected mode where UEs perform handovers between cells. The focus is on mobility optimization when UEs are in connected mode. Both modes can trigger intra-LTE mobility between eNBs or inter-LTE mobility such as handovers to 3G/2G networks. Handover contains measurement and reporting, preparation, and execution phases, and fine-tuning measurement parameters can help avoid issues like ping-ponging.