Network Utilization Improvement via a Predictive Load Scheduling Scheme in Heterogeneous Wireless Networks

In heterogeneous wireless networks (HWNs), the large-coverage cellular networks are usually overlaid with denser small-coverage microcells, wireless local area networks (WLANs), femtocells, and even relays. To prevent unbalanced load distribution in these HWNs from decreasing network utilization and degrading the quality of service (QoS), load scheduling between the overlaid networks is essential and should be reasonably designed. In fact, unbalanced load distribution can be directly reflected by the idle durations of networks and channels. In this paper, a predictive load scheduling scheme is proposed from the point of decreasing the capacity-weighted idle durations of networks and channels. For the proposed scheme, a fairly general HWNs scenario is considered, the scheduling problem is formulated, an iteration-based predictive method is given to obtain the idle duration, and a gradient descent method is derived for the optimal scheduled load. In the simulation, the effectiveness of the idle duration prediction method is validated, and the simulation results show that the proposed load scheduling scheme can greatly improve the network utilization and QoS.