Handover Reduction via Joint Bandwidth Allocation and CAC in Randomly Distributed HCNs

For heterogeneous cellular networks (HCNs) with different cell size levels, the connection of high-mobility user equipment (UE) is a problem due to its short residence time in micro cell. In the former investigations, high-mobility UEs are always distributed to macro base stations (BSs) with reserved bandwidth, which is not an optimal solution to reduce handovers indeed. In this paper, a joint bandwidth allocation and call admission control (CAC) strategy is proposed to reduce handovers, that some high-mobility UEs are distributed to macro BSs for larger residence time, while the other high-mobility UEs are distributed to micro BSs for larger bandwidth. A scenario of randomly distributed HCNs with shared bandwidth and reserved bandwidth is considered. The joint bandwidth allocation and CAC problem is formulated based on the stochastic geometry modeling. A two-stage iteration method is given to obtain the optimal solutions. This work may shed some light for future extension and study.