Reducing connection failure in mobility management for LTE HetNet using MCDM algorithm

Heterogeneous network (HetNet) deploying a number of small cells in a macro cell improves network capacity as well as data rate at hot spots and cell edges. The mobility management with HetNet is challenging due to its complexity. In this paper an efficient handover scheme is proposed considering the asymmetric characteristics of macro and pico cells in HetNet. The proposed scheme ranks the candidate cells for handover using a multi-criteria decision making (MCDM) algorithm and the information on the movement of user equipment (UE). When the received power is too low, if the UE can detect a suitable target eNB of good quality, handover is triggered promptly even before the time-to-trigger window expires to avoid radio link failure. Even though the received signal from the serving cell is high enough for communication, handover is also triggered for the UE when the downlink SINR is below a threshold. The performance of the proposed scheme is evaluated by computer simulation and compared with two well-known handover algorithms with respect to the number of handovers per second, goodput per UE, and packet loss rate. The simulation with LTE-Sim reveals that the proposed scheme significantly enhances the goodput while reducing packet loss and unnecessary handover.