Mobility management challenges in 3GPP heterogeneous networks

In this article we provide a comprehensive review of the handover process in heterogeneous networks (HetNets), and identify technical challenges in mobility management. In this line, we evaluate the mobility performance of HetNets with the 3rd Generation Partnership Project (3GPP) Release-10 range expansion and enhanced inter-cell interference coordination (eICIC) features such as almost blank subframes (ABSFs). Simulation assumptions and parameters of a related study item in 3GPP are used to investigate the impact of various handover parameters on mobility performance. In addition, we propose a mobility-based inter-cell interference coordination (MB-ICIC) scheme, in which picocells configure coordinated resources so that macrocells can schedule their high-mobility UEs in these resources without co-channel interference from picocells. MB-ICIC also benefits low-mobility UEs, since handover parameters can now be more flexibly optimized. Simulations using the 3GPP simulation assumptions are performed to evaluate the performance of MB-ICIC under several scenarios.