Energy Efficient Mobility Enhancement in LTE Pico–Macro HetNet Systems

Mobility management plays an important role in heterogeneous networks (HetNets), because it helps to reduce radio link failures, handover delays, and power consumption, and enhances offloading benefits. In the present study, two cases are identified regarding mobility in HetNets. The first one is related to signaling and the second one is related to data transmission; i.e., handover and link rate adaptation. It has been shown that both processes are affected by the user mobility level and that performance deteriorates near cell edges. The aim is to optimize the user offloading to picocells depending on their estimated speeds so that overall system performance is maximized. The network-centric solution and cooperation between cells that achieve seamless handover is presented, and the impact of the performed measurements for link adaptation during motion is investigated.