  Cellular operators are continuously densifying their networks to cope with
the ever-increasing capacity demand. Furthermore, an extreme densification
phase for cellular networks is foreseen to fulfill the ambitious fifth
generation (5G) performance requirements. Network densification improves
spectrum utilization and network capacity by shrinking base stations' (BSs)
footprints and reusing the same spectrum more frequently over the spatial
domain. However, network densification also increases the handover (HO) rate,
which may diminish the capacity gains for mobile users due to HO delays. In
highly dense 5G cellular networks, HO delays may neutralize or even negate the
gains offered by network densification. In this paper, we present an analytical
paradigm, based on stochastic geometry, to quantify the effect of HO delay on
the average user rate in cellular networks. To this end, we propose a flexible
handover scheme to reduce HO delay in case of highly dense cellular networks.
This scheme allows skipping the HO procedure with some BSs along users'
trajectories. The performance evaluation and testing of this scheme for only
single HO skipping shows considerable gains in many practical scenarios.
