  Despite the central role of mobility in wireless networks, analytical study
on its impact on network performance is notoriously difficult. This paper aims
to address this gap by proposing a random waypoint (RWP) mobility model defined
on the entire plane and applying it to analyze two key cellular network
parameters: handover rate and sojourn time. We first analyze the stochastic
properties of the proposed model and compare it to two other models: the
classical RWP mobility model and a synthetic truncated Levy walk model which is
constructed from real mobility trajectories. The comparison shows that the
proposed RWP mobility model is more appropriate for the mobility simulation in
emerging cellular networks, which have ever-smaller cells. Then we apply the
proposed model to cellular networks under both deterministic (hexagonal) and
random (Poisson) base station (BS) models. We present analytic expressions for
both handover rate and sojourn time, which have the expected property that the
handover rate is proportional to the square root of BS density. Compared to an
actual BS distribution, we find that the Poisson-Voronoi model is about as
accurate in terms of mobility evaluation as hexagonal model, though being more
pessimistic in that it predicts a higher handover rate and lower sojourn time.
