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

Abstract

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.