Modeling Delay Timer Algorithm for Handover Reduction in Heterogeneous Radio Access Networks

Consisting of both small cells and a macro cell, the heterogeneous radio access network (Het-RAN) provides transmission service with higher data rate, offloads data traffic from the macro cell, and expands the service area of the macro cell. However, due to the small and non-continuous service areas of the small cells, frequent handover executions (i.e., significant handover cost) occur in the Het-RAN. To resolve the issue, we have proposed a delay timer algorithm (DTA) in our previous works. In this paper, we propose an analytical model to study the effects of the application traffic (based on the ETSI traffic model) and the user equipment (UE) mobility model on the performance of the DTA. We assume general distributions in the UE mobility model, so the analytical model is flexible enough for performance evaluation of the real Het-RAN system. We also construct a simulation model. The analytical model is validated against the simulation model. This analysis can help network operators run the Het-RAN more efficiently and effectively.