To efficiently plan future personal communications services, we need to solve various mobility/traffic problems in one dimensional (1-D), two-dimensional (2-D), and three-dimensional (3-D) micro- or pico-cell environments. Although many users exhibit vertical motion inside elevators in high-rise buildings, there have been no studies regarding cell planning which take into account vertical motion with elevators, In this paper, we extend the previous 3-D indoor mobility modeling by considering the proper boundary conditions on each floor and vertical motions through elevators and modeling mobility in high-rise buildings in order to estimate the number of handoffs, We then propose a blocking probability model with mobility as a traffic model in 3-D indoor environments, Using this model, we can obtain the required number of channels per cell under the given blocking probability constraint. These results can be used in planning the networks of future personal communications services.