Modeling and analysis of handover failure probability in small cell networks

Mobility management in small cell networks is of utmost importance, and is currently under study in 3GPP Release-12. In this article, we model and analyze the outbound handover failure probability in small cell networks, in which a given user crosses its serving cell coverage border before his time-to-trigger elapses, without connecting to his target base station. Using tools from stochastic geometry, a closed-form expression of the handover link failure probability is characterized, as a function of shadowed channel fading, hysteresis margin, time-to-trigger, users' velocity and traveled distances. Numerical results show the effectiveness of the proposed analytical model and provide key insights into the problem of mobility management.