Impact of channel fading on mobility management in heterogeneous networks

Handover decisions and mobility management in modern communication networks are carried out using signal measurements taken at user equipment (UE), obtained from neighboring base stations. Therefore, time and frequency selective characteristics of the radio propagation channel can seriously degrade the handover performance. In this paper, we investigate the impact of channel fading on the handover failure performance in densely deployed heterogeneous networks. We introduce a simple geometric model to analyze handover failure as a function of key mobility management parameters. Relevant fading statistics are extracted from a 3GPP-compliant heterogeneous network simulator, and a semi-analytic approach is followed to obtain the handover failure performance of a mobile UE. Theoretical findings are verified through simulations, which show that when channel fading is considered, handover performance can be significantly degraded even at low mobile velocities.