Prediction handover trigger scheme for reducing handover latency in two-tier Femtocell networks

Service continuity in two-tier Femtocell networks, especially impaired by the handover latency, remains as a problem to be solved. Motivated by this problems, a Layer 3 prediction handover scheme is proposed, which can be integrated into the user equipment (UE) part of industry-preferable mobile-assisted network-controlled handover (MANCH). The main contributions of the proposed scheme include: 1) based on time series analysis theory, the prediction model of Layer 3 (L3) filtered reference signal received power (RSRP) is constructed to activate L3 handover prior to Layer 2 (L2) handover procedure; 2) in order to improve the reliability and robustness of the L3 prediction model, a two-priority handover trigger event evaluation method is designed, where the classical and prediction handover trigger event evaluation parts co-exist, and the former is prior to the latter; 3) the relationship between defined prediction handover gain (PHG) and the probability of false handover prediction trigger is derived. In simulations, to evaluate the robustness of the proposed scheme, a module of UEs´ movement pattern is designed, considering characteristics of the UE´s movement pattern. Results of the performance evaluation show that handover latency of indoor handover UEs can be effectively reduced with high prediction accuracy.