In this paper we study the so-called random waypoint (RWP) mobility model in the context of cellular networks. In the RWP model the nodes, i.e. mobile users, move along a zigzag path consisting of straight legs from one waypoint to the next. Each waypoint is assumed to be drawn from the uniform distribution over the given convex domain. In this paper we characterise the key performance measures, mean handover rate and mean sojourn time from the point of view of an arbitrary cell, as well as the mean handover rate in the network. We present an exact analytical formula for the mean arrival rate across an arbitrary curve, which, together with the pdf of the node location, allows us to compute all other interesting measures. The results are illustrated by several numerical examples.