Mobility Sensitivity Analysis for LTE-Advanced HetNet Deployments with Dual Connectivity

A mobility performance sensitivity analysis is presented for Dual Connectivity cases where the users can be served simultaneously by a macro and a small cell. The performance is assessed for the 3GPP generic simulation scenario and for two site specific cases, with the aim of comparing the results coming from these different scenarios. The site-specific scenarios are based on detailed topography map data and advanced ray-tracing techniques. It is generally found that the first order statistics and overall conclusions are in good alignment for the considered environments. However, there are also a number of differences in the obtained performance results for the different cases, e.g. in terms of small cell time-of-stay statistics. The explicit modeling of streets and building topology, propagation in street canyons, etc., is found to have an important impact on the mobility performance. Especially the time-of-stay statistics and the location of handover failures differ between generic 3GPP case and the site-specific modeling scenarios. So, although general trends and observations from simulations based on the 3GPP defined scenario are valuable, one should be cautious by drawing too strong conclusions as not all performance-determining effects are accurately included in such generic models.